diff --git a/packages/server/modules/gatekeeper/clients/stripe.ts b/packages/server/modules/gatekeeper/clients/stripe.ts
index cb61b692f..8d68d64b6 100644
--- a/packages/server/modules/gatekeeper/clients/stripe.ts
+++ b/packages/server/modules/gatekeeper/clients/stripe.ts
@@ -2,8 +2,8 @@
 import {
   CreateCheckoutSession,
   GetSubscriptionData,
-  SubscriptionData,
-  WorkspaceSubscription
+  ReconcileSubscriptionData,
+  SubscriptionData
 } from '@/modules/gatekeeper/domain/billing'
 import {
   WorkspacePlanBillingIntervals,
@@ -163,19 +163,13 @@ export const parseSubscriptionData = (
 // this should be a reconcile subscriptions, we keep an accurate state in the DB
 // on each change, we're reconciling that state to stripe
 export const reconcileWorkspaceSubscriptionFactory =
-  ({ stripe }: { stripe: Stripe }) =>
-  async ({
-    workspaceSubscription,
-    applyProrotation
-  }: {
-    workspaceSubscription: WorkspaceSubscription
-    applyProrotation: boolean
-  }) => {
+  ({ stripe }: { stripe: Stripe }): ReconcileSubscriptionData =>
+  async ({ subscriptionData, applyProrotation }) => {
     const existingSubscriptionState = await getSubscriptionDataFactory({ stripe })({
-      subscriptionId: workspaceSubscription.subscriptionData.subscriptionId
+      subscriptionId: subscriptionData.subscriptionId
     })
     const items: Stripe.SubscriptionUpdateParams.Item[] = []
-    for (const product of workspaceSubscription.subscriptionData.products) {
+    for (const product of subscriptionData.products) {
       const existingProduct = existingSubscriptionState.products.find(
         (p) => p.productId === product.productId
       )
@@ -187,13 +181,16 @@ export const reconcileWorkspaceSubscriptionFactory =
         items.push({ quantity: product.quantity, price: product.priceId })
         items.push({ id: product.subscriptionItemId, deleted: true })
       } else {
-        items.push({ quantity: product.quantity, id: product.subscriptionItemId })
+        items.push({
+          quantity: product.quantity,
+          id: existingProduct.subscriptionItemId
+        })
       }
     }
     // workspaceSubscription.subscriptionData.products.
     // const item = workspaceSubscription.subscriptionData.products.find(p => p.)
-    await stripe.subscriptions.update(
-      workspaceSubscription.subscriptionData.subscriptionId,
-      { items, proration_behavior: applyProrotation ? 'create_prorations' : 'none' }
-    )
+    await stripe.subscriptions.update(subscriptionData.subscriptionId, {
+      items,
+      proration_behavior: applyProrotation ? 'create_prorations' : 'none'
+    })
   }
diff --git a/packages/server/modules/gatekeeper/domain/billing.ts b/packages/server/modules/gatekeeper/domain/billing.ts
index f26c2c39d..3ee6c87e7 100644
--- a/packages/server/modules/gatekeeper/domain/billing.ts
+++ b/packages/server/modules/gatekeeper/domain/billing.ts
@@ -5,6 +5,7 @@ import {
   WorkspacePlanBillingIntervals,
   WorkspacePricingPlans
 } from '@/modules/gatekeeper/domain/workspacePricing'
+import { OverrideProperties } from 'type-fest'
 import { z } from 'zod'
 
 export type UnpaidWorkspacePlanStatuses = 'valid'
@@ -109,6 +110,15 @@ export type WorkspaceSubscription = {
   billingInterval: WorkspacePlanBillingIntervals
   subscriptionData: SubscriptionData
 }
+const subscriptionProduct = z.object({
+  productId: z.string(),
+  subscriptionItemId: z.string(),
+  priceId: z.string(),
+  quantity: z.number()
+})
+
+type SubscriptionProduct = z.infer<typeof subscriptionProduct>
+
 export const subscriptionData = z.object({
   subscriptionId: z.string().min(1),
   customerId: z.string().min(1),
@@ -123,15 +133,7 @@ export const subscriptionData = z.object({
     z.literal('unpaid'),
     z.literal('paused')
   ]),
-  products: z
-    .object({
-      // we're going to use the productId to match with our
-      productId: z.string(),
-      subscriptionItemId: z.string(),
-      priceId: z.string(),
-      quantity: z.number()
-    })
-    .array()
+  products: subscriptionProduct.array()
 })
 
 // this abstracts the stripe sub data
@@ -158,7 +160,18 @@ export type GetWorkspacePlanPrice = (args: {
   billingInterval: WorkspacePlanBillingIntervals
 }) => string
 
-export type ReconcileWorkspaceSubscription = (args: {
-  workspaceSubscription: WorkspaceSubscription
+export type GetWorkspacePlanProductId = (args: {
+  workspacePlan: WorkspacePricingPlans
+}) => string
+
+export type SubscriptionDataInput = OverrideProperties<
+  SubscriptionData,
+  {
+    products: OverrideProperties<SubscriptionProduct, { subscriptionItemId?: string }>[]
+  }
+>
+
+export type ReconcileSubscriptionData = (args: {
+  subscriptionData: SubscriptionDataInput
   applyProrotation: boolean
 }) => Promise<void>
diff --git a/packages/server/modules/gatekeeper/events/eventListener.ts b/packages/server/modules/gatekeeper/events/eventListener.ts
new file mode 100644
index 000000000..e2ae7fc97
--- /dev/null
+++ b/packages/server/modules/gatekeeper/events/eventListener.ts
@@ -0,0 +1,40 @@
+import { reconcileWorkspaceSubscriptionFactory } from '@/modules/gatekeeper/clients/stripe'
+import {
+  getWorkspacePlanFactory,
+  getWorkspaceSubscriptionFactory
+} from '@/modules/gatekeeper/repositories/billing'
+import { addWorkspaceSubscriptionSeatIfNeededFactory } from '@/modules/gatekeeper/services/subscriptions'
+import {
+  getWorkspacePlanPrice,
+  getWorkspacePlanProductId
+} from '@/modules/gatekeeper/stripe'
+import { getEventBus } from '@/modules/shared/services/eventBus'
+import { countWorkspaceRoleWithOptionalProjectRoleFactory } from '@/modules/workspaces/repositories/workspaces'
+import { WorkspaceEvents } from '@/modules/workspacesCore/domain/events'
+import { Knex } from 'knex'
+import Stripe from 'stripe'
+
+export const initializeEventListenersFactory =
+  ({ db, stripe }: { db: Knex; stripe: Stripe }) =>
+  () => {
+    const eventBus = getEventBus()
+    const quitCbs = [
+      eventBus.listen(WorkspaceEvents.RoleUpdated, async ({ payload }) => {
+        const addWorkspaceSubscriptionSeatIfNeeded =
+          addWorkspaceSubscriptionSeatIfNeededFactory({
+            getWorkspacePlan: getWorkspacePlanFactory({ db }),
+            getWorkspaceSubscription: getWorkspaceSubscriptionFactory({ db }),
+            countWorkspaceRole: countWorkspaceRoleWithOptionalProjectRoleFactory({
+              db
+            }),
+            getWorkspacePlanPrice,
+            getWorkspacePlanProductId,
+            reconcileSubscriptionData: reconcileWorkspaceSubscriptionFactory({ stripe })
+          })
+
+        await addWorkspaceSubscriptionSeatIfNeeded(payload)
+      })
+    ]
+
+    return () => quitCbs.forEach((quit) => quit())
+  }
diff --git a/packages/server/modules/gatekeeper/index.ts b/packages/server/modules/gatekeeper/index.ts
index ba6cf40c9..7dca178ab 100644
--- a/packages/server/modules/gatekeeper/index.ts
+++ b/packages/server/modules/gatekeeper/index.ts
@@ -6,6 +6,8 @@ import { getBillingRouter } from '@/modules/gatekeeper/rest/billing'
 import { registerOrUpdateScopeFactory } from '@/modules/shared/repositories/scopes'
 import { db } from '@/db/knex'
 import { gatekeeperScopes } from '@/modules/gatekeeper/scopes'
+import { initializeEventListenersFactory } from '@/modules/gatekeeper/events/eventListener'
+import { getStripeClient } from '@/modules/gatekeeper/stripe'
 
 const { FF_GATEKEEPER_MODULE_ENABLED, FF_BILLING_INTEGRATION_ENABLED } =
   getFeatureFlags()
@@ -15,6 +17,8 @@ const initScopes = async () => {
   await Promise.all(gatekeeperScopes.map((scope) => registerFunc({ scope })))
 }
 
+let quitListeners: (() => void) | undefined = undefined
+
 const gatekeeperModule: SpeckleModule = {
   async init(app, isInitial) {
     await initScopes()
@@ -35,6 +39,11 @@ const gatekeeperModule: SpeckleModule = {
       if (FF_BILLING_INTEGRATION_ENABLED) {
         app.use(getBillingRouter())
 
+        quitListeners = initializeEventListenersFactory({
+          db,
+          stripe: getStripeClient()
+        })()
+
         const isLicenseValid = await validateModuleLicense({
           requiredModules: ['billing']
         })
@@ -45,6 +54,9 @@ const gatekeeperModule: SpeckleModule = {
         // TODO: create a cron job, that removes unused seats from the subscription at the beginning of each workspace plan's billing cycle
       }
     }
+  },
+  async shutdown() {
+    if (quitListeners) quitListeners()
   }
 }
 export = gatekeeperModule
diff --git a/packages/server/modules/gatekeeper/services/subscriptions.ts b/packages/server/modules/gatekeeper/services/subscriptions.ts
index 1d2553632..dcca63737 100644
--- a/packages/server/modules/gatekeeper/services/subscriptions.ts
+++ b/packages/server/modules/gatekeeper/services/subscriptions.ts
@@ -1,8 +1,13 @@
 import {
   GetWorkspacePlan,
+  GetWorkspacePlanPrice,
+  GetWorkspacePlanProductId,
+  GetWorkspaceSubscription,
   GetWorkspaceSubscriptionBySubscriptionId,
   PaidWorkspacePlanStatuses,
+  ReconcileSubscriptionData,
   SubscriptionData,
+  SubscriptionDataInput,
   UpsertPaidWorkspacePlan,
   UpsertWorkspaceSubscription
 } from '@/modules/gatekeeper/domain/billing'
@@ -11,7 +16,9 @@ import {
   WorkspacePlanNotFoundError,
   WorkspaceSubscriptionNotFoundError
 } from '@/modules/gatekeeper/errors/billing'
-import { throwUncoveredError } from '@speckle/shared'
+import { CountWorkspaceRoleWithOptionalProjectRole } from '@/modules/workspaces/domain/operations'
+import { throwUncoveredError, WorkspaceRoles } from '@speckle/shared'
+import { cloneDeep, sum } from 'lodash'
 
 export const handleSubscriptionUpdateFactory =
   ({
@@ -74,7 +81,92 @@ export const handleSubscriptionUpdateFactory =
       })
       // if there is a status in the sub, we recognize, we need to update our state
       await upsertWorkspaceSubscription({
-        workspaceSubscription: { ...subscription, subscriptionData }
+        workspaceSubscription: {
+          ...subscription,
+          updatedAt: new Date(),
+          subscriptionData
+        }
       })
     }
   }
+
+export const addWorkspaceSubscriptionSeatIfNeededFactory =
+  ({
+    getWorkspacePlan,
+    getWorkspaceSubscription,
+    countWorkspaceRole,
+    getWorkspacePlanProductId,
+    getWorkspacePlanPrice,
+    reconcileSubscriptionData
+  }: {
+    getWorkspacePlan: GetWorkspacePlan
+    getWorkspaceSubscription: GetWorkspaceSubscription
+    countWorkspaceRole: CountWorkspaceRoleWithOptionalProjectRole
+    getWorkspacePlanProductId: GetWorkspacePlanProductId
+    getWorkspacePlanPrice: GetWorkspacePlanPrice
+    reconcileSubscriptionData: ReconcileSubscriptionData
+  }) =>
+  async ({ workspaceId, role }: { workspaceId: string; role: WorkspaceRoles }) => {
+    const workspacePlan = await getWorkspacePlan({ workspaceId })
+    if (!workspacePlan) throw new WorkspacePlanNotFoundError()
+    const workspaceSubscription = await getWorkspaceSubscription({ workspaceId })
+    if (!workspaceSubscription) throw new WorkspaceSubscriptionNotFoundError()
+
+    switch (workspacePlan.name) {
+      case 'team':
+      case 'pro':
+      case 'business':
+        break
+      case 'unlimited':
+      case 'academia':
+        throw new WorkspacePlanMismatchError()
+      default:
+        throwUncoveredError(workspacePlan)
+    }
+
+    let productId: string
+    let priceId: string
+    let roleCount: number
+    switch (role) {
+      case 'workspace:guest':
+        roleCount = await countWorkspaceRole({ workspaceId, workspaceRole: role })
+        productId = getWorkspacePlanProductId({ workspacePlan: 'guest' })
+        priceId = getWorkspacePlanPrice({
+          workspacePlan: 'guest',
+          billingInterval: workspaceSubscription.billingInterval
+        })
+        break
+      case 'workspace:admin':
+      case 'workspace:member':
+        roleCount = sum(
+          await Promise.all([
+            countWorkspaceRole({ workspaceId, workspaceRole: 'workspace:admin' }),
+            countWorkspaceRole({ workspaceId, workspaceRole: 'workspace:member' })
+          ])
+        )
+        productId = getWorkspacePlanProductId({ workspacePlan: workspacePlan.name })
+        priceId = getWorkspacePlanPrice({
+          workspacePlan: workspacePlan.name,
+          billingInterval: workspaceSubscription.billingInterval
+        })
+        break
+      default:
+        throwUncoveredError(role)
+    }
+
+    const subscriptionData: SubscriptionDataInput = cloneDeep(
+      workspaceSubscription.subscriptionData
+    )
+
+    const currentPlanProduct = subscriptionData.products.find(
+      (product) => product.productId === productId
+    )
+    if (!currentPlanProduct) {
+      subscriptionData.products.push({ productId, priceId, quantity: roleCount })
+    } else {
+      // if there is enough seats, we do not have to do anything
+      if (currentPlanProduct.quantity >= roleCount) return
+      currentPlanProduct.quantity = roleCount
+    }
+    await reconcileSubscriptionData({ subscriptionData, applyProrotation: true })
+  }
diff --git a/packages/server/modules/gatekeeper/stripe.ts b/packages/server/modules/gatekeeper/stripe.ts
index 4fa6cd597..d1ae3bb17 100644
--- a/packages/server/modules/gatekeeper/stripe.ts
+++ b/packages/server/modules/gatekeeper/stripe.ts
@@ -1,4 +1,7 @@
-import { GetWorkspacePlanPrice } from '@/modules/gatekeeper/domain/billing'
+import {
+  GetWorkspacePlanPrice,
+  GetWorkspacePlanProductId
+} from '@/modules/gatekeeper/domain/billing'
 import {
   WorkspacePlanBillingIntervals,
   WorkspacePricingPlans
@@ -43,3 +46,7 @@ export const getWorkspacePlanPrice: GetWorkspacePlanPrice = ({
   workspacePlan,
   billingInterval
 }) => workspacePlanPrices()[workspacePlan][billingInterval]
+
+export const getWorkspacePlanProductId: GetWorkspacePlanProductId = ({
+  workspacePlan
+}) => workspacePlanPrices()[workspacePlan].productId
diff --git a/packages/server/modules/gatekeeper/tests/unit/subscriptions.spec.ts b/packages/server/modules/gatekeeper/tests/unit/subscriptions.spec.ts
index 1066bfadb..25e082a87 100644
--- a/packages/server/modules/gatekeeper/tests/unit/subscriptions.spec.ts
+++ b/packages/server/modules/gatekeeper/tests/unit/subscriptions.spec.ts
@@ -1,5 +1,6 @@
 import {
   SubscriptionData,
+  SubscriptionDataInput,
   WorkspacePlan,
   WorkspaceSubscription
 } from '@/modules/gatekeeper/domain/billing'
@@ -8,11 +9,15 @@ import {
   WorkspacePlanNotFoundError,
   WorkspaceSubscriptionNotFoundError
 } from '@/modules/gatekeeper/errors/billing'
-import { handleSubscriptionUpdateFactory } from '@/modules/gatekeeper/services/subscriptions'
+import {
+  addWorkspaceSubscriptionSeatIfNeededFactory,
+  handleSubscriptionUpdateFactory
+} from '@/modules/gatekeeper/services/subscriptions'
 import { expectToThrow } from '@/test/assertionHelper'
+import { throwUncoveredError } from '@speckle/shared'
 import { expect } from 'chai'
 import cryptoRandomString from 'crypto-random-string'
-import { merge } from 'lodash'
+import { assign } from 'lodash'
 
 const createTestSubscriptionData = (
   overrides: Partial<SubscriptionData> = {}
@@ -31,7 +36,21 @@ const createTestSubscriptionData = (
     status: 'active',
     subscriptionId: cryptoRandomString({ length: 10 })
   }
-  return merge(defaultValues, overrides)
+  return assign(defaultValues, overrides)
+}
+
+const createTestWorkspaceSubscription = (
+  overrides: Partial<WorkspaceSubscription> = {}
+): WorkspaceSubscription => {
+  const defaultValues: WorkspaceSubscription = {
+    billingInterval: 'monthly',
+    createdAt: new Date(),
+    updatedAt: new Date(),
+    currentBillingCycleEnd: new Date(),
+    subscriptionData: createTestSubscriptionData(),
+    workspaceId: cryptoRandomString({ length: 10 })
+  }
+  return assign(defaultValues, overrides)
 }
 
 describe('subscriptions @gatekeeper', () => {
@@ -58,14 +77,8 @@ describe('subscriptions @gatekeeper', () => {
       const subscriptionData = createTestSubscriptionData()
       const err = await expectToThrow(async () => {
         await handleSubscriptionUpdateFactory({
-          getWorkspaceSubscriptionBySubscriptionId: async () => ({
-            subscriptionData,
-            billingInterval: 'monthly',
-            createdAt: new Date(),
-            updatedAt: new Date(),
-            currentBillingCycleEnd: new Date(),
-            workspaceId: cryptoRandomString({ length: 10 })
-          }),
+          getWorkspaceSubscriptionBySubscriptionId: async () =>
+            createTestWorkspaceSubscription({ subscriptionData }),
           getWorkspacePlan: async () => null,
           upsertWorkspaceSubscription: async () => {
             expect.fail()
@@ -83,14 +96,11 @@ describe('subscriptions @gatekeeper', () => {
         const workspaceId = cryptoRandomString({ length: 10 })
         const err = await expectToThrow(async () => {
           await handleSubscriptionUpdateFactory({
-            getWorkspaceSubscriptionBySubscriptionId: async () => ({
-              subscriptionData,
-              billingInterval: 'monthly',
-              createdAt: new Date(),
-              updatedAt: new Date(),
-              currentBillingCycleEnd: new Date(),
-              workspaceId
-            }),
+            getWorkspaceSubscriptionBySubscriptionId: async () =>
+              createTestWorkspaceSubscription({
+                subscriptionData,
+                workspaceId
+              }),
             getWorkspacePlan: async () => ({ name, workspaceId, status: 'valid' }),
             upsertWorkspaceSubscription: async () => {
               expect.fail()
@@ -109,14 +119,10 @@ describe('subscriptions @gatekeeper', () => {
         cancelAt: new Date(2099, 12, 31)
       })
       const workspaceId = cryptoRandomString({ length: 10 })
-      const workspaceSubscription = {
+      const workspaceSubscription = createTestWorkspaceSubscription({
         subscriptionData,
-        billingInterval: 'monthly' as const,
-        createdAt: new Date(),
-        updatedAt: new Date(),
-        currentBillingCycleEnd: new Date(),
         workspaceId
-      }
+      })
 
       let updatedSubscription: WorkspaceSubscription | undefined = undefined
       let updatedPlan: WorkspacePlan | undefined = undefined
@@ -170,14 +176,11 @@ describe('subscriptions @gatekeeper', () => {
         status: 'past_due'
       })
       const workspaceId = cryptoRandomString({ length: 10 })
-      const workspaceSubscription = {
+
+      const workspaceSubscription = createTestWorkspaceSubscription({
         subscriptionData,
-        billingInterval: 'monthly' as const,
-        createdAt: new Date(),
-        updatedAt: new Date(),
-        currentBillingCycleEnd: new Date(),
         workspaceId
-      }
+      })
 
       let updatedSubscription: WorkspaceSubscription | undefined = undefined
       let updatedPlan: WorkspacePlan | undefined = undefined
@@ -233,14 +236,11 @@ describe('subscriptions @gatekeeper', () => {
           status
         })
         const workspaceId = cryptoRandomString({ length: 10 })
-        const workspaceSubscription = {
+
+        const workspaceSubscription = createTestWorkspaceSubscription({
           subscriptionData,
-          billingInterval: 'monthly' as const,
-          createdAt: new Date(),
-          updatedAt: new Date(),
-          currentBillingCycleEnd: new Date(),
           workspaceId
-        }
+        })
 
         await handleSubscriptionUpdateFactory({
           getWorkspaceSubscriptionBySubscriptionId: async () => workspaceSubscription,
@@ -259,4 +259,365 @@ describe('subscriptions @gatekeeper', () => {
       })
     })
   })
+  describe('addWorkspaceSubscriptionSeatIfNeededFactory returns a function, that', () => {
+    it('throws if the workspacePlan is not found', async () => {
+      const workspaceId = cryptoRandomString({ length: 10 })
+      const addWorkspaceSubscriptionSeatIfNeeded =
+        addWorkspaceSubscriptionSeatIfNeededFactory({
+          getWorkspacePlan: async () => null,
+          getWorkspaceSubscription: async () => {
+            expect.fail()
+          },
+          countWorkspaceRole: async () => {
+            expect.fail()
+          },
+          getWorkspacePlanPrice: () => {
+            expect.fail()
+          },
+          getWorkspacePlanProductId: () => {
+            expect.fail()
+          },
+          reconcileSubscriptionData: async () => {
+            expect.fail()
+          }
+        })
+      const err = await expectToThrow(async () => {
+        await addWorkspaceSubscriptionSeatIfNeeded({
+          workspaceId,
+          role: 'workspace:admin'
+        })
+      })
+      expect(err.message).to.equal(new WorkspacePlanNotFoundError().message)
+    })
+    it('throws if the workspaceSubscription is not found', async () => {
+      const workspaceId = cryptoRandomString({ length: 10 })
+      const addWorkspaceSubscriptionSeatIfNeeded =
+        addWorkspaceSubscriptionSeatIfNeededFactory({
+          getWorkspacePlan: async () => ({
+            name: 'unlimited',
+            workspaceId,
+            status: 'valid'
+          }),
+          getWorkspaceSubscription: async () => null,
+          countWorkspaceRole: async () => {
+            expect.fail()
+          },
+          getWorkspacePlanPrice: () => {
+            expect.fail()
+          },
+          getWorkspacePlanProductId: () => {
+            expect.fail()
+          },
+          reconcileSubscriptionData: async () => {
+            expect.fail()
+          }
+        })
+      const err = await expectToThrow(async () => {
+        await addWorkspaceSubscriptionSeatIfNeeded({
+          workspaceId,
+          role: 'workspace:admin'
+        })
+      })
+      expect(err.message).to.equal(new WorkspaceSubscriptionNotFoundError().message)
+    })
+    it('throws if a non paid plan, has a subscription', async () => {
+      const workspaceId = cryptoRandomString({ length: 10 })
+      const subscriptionData = createTestSubscriptionData({ products: [] })
+      const workspaceSubscription = createTestWorkspaceSubscription({
+        workspaceId,
+        subscriptionData
+      })
+      const addWorkspaceSubscriptionSeatIfNeeded =
+        addWorkspaceSubscriptionSeatIfNeededFactory({
+          getWorkspacePlan: async () => ({
+            name: 'unlimited',
+            workspaceId,
+            status: 'valid'
+          }),
+          getWorkspaceSubscription: async () => workspaceSubscription,
+          countWorkspaceRole: async () => {
+            expect.fail()
+          },
+          getWorkspacePlanPrice: () => {
+            expect.fail()
+          },
+          getWorkspacePlanProductId: () => {
+            expect.fail()
+          },
+          reconcileSubscriptionData: async () => {
+            expect.fail()
+          }
+        })
+      const err = await expectToThrow(async () => {
+        await addWorkspaceSubscriptionSeatIfNeeded({
+          workspaceId,
+          role: 'workspace:admin'
+        })
+      })
+      expect(err.message).to.equal(new WorkspacePlanMismatchError().message)
+    })
+    it('uses the guest count, guest product and price id if the new role is workspace:guest', async () => {
+      const workspaceId = cryptoRandomString({ length: 10 })
+      const subscriptionData = createTestSubscriptionData({ products: [] })
+      const workspaceSubscription = createTestWorkspaceSubscription({
+        workspaceId,
+        subscriptionData
+      })
+      const workspacePlan: WorkspacePlan = {
+        name: 'team',
+        workspaceId,
+        status: 'valid'
+      }
+      const priceId = cryptoRandomString({ length: 10 })
+      const productId = cryptoRandomString({ length: 10 })
+      const roleCount = 10
+
+      let reconciledSubscriptionData: SubscriptionDataInput | undefined = undefined
+      const addWorkspaceSubscriptionSeatIfNeeded =
+        addWorkspaceSubscriptionSeatIfNeededFactory({
+          getWorkspacePlan: async () => workspacePlan,
+          getWorkspaceSubscription: async () => workspaceSubscription,
+          countWorkspaceRole: async ({ workspaceRole }) => {
+            switch (workspaceRole) {
+              case 'workspace:admin':
+              case 'workspace:member':
+                expect.fail()
+              case 'workspace:guest':
+                return roleCount
+            }
+          },
+          getWorkspacePlanPrice: ({ workspacePlan, billingInterval }) => {
+            if (billingInterval !== workspaceSubscription.billingInterval) expect.fail()
+            switch (workspacePlan) {
+              case 'business':
+              case 'team':
+              case 'pro':
+                expect.fail()
+              case 'guest':
+                return priceId
+              default:
+                throwUncoveredError(workspacePlan)
+            }
+          },
+          getWorkspacePlanProductId: (args) => {
+            if (args.workspacePlan !== 'guest') expect.fail()
+            return productId
+          },
+          reconcileSubscriptionData: async ({ applyProrotation, subscriptionData }) => {
+            if (!applyProrotation) expect.fail()
+            reconciledSubscriptionData = subscriptionData
+          }
+        })
+      await addWorkspaceSubscriptionSeatIfNeeded({
+        workspaceId,
+        role: 'workspace:guest'
+      })
+      expect(reconciledSubscriptionData!.products).deep.equalInAnyOrder([
+        { productId, priceId, quantity: roleCount }
+      ])
+    })
+    ;(['workspace:member', 'workspace:admin'] as const).forEach((role) =>
+      it(`uses the admin + member count, workspacePlan product and price id if the new role is ${role}`, async () => {
+        const workspaceId = cryptoRandomString({ length: 10 })
+        const subscriptionData = createTestSubscriptionData({ products: [] })
+        const workspaceSubscription = createTestWorkspaceSubscription({
+          workspaceId,
+          subscriptionData
+        })
+        const workspacePlan: WorkspacePlan = {
+          name: 'team',
+          workspaceId,
+          status: 'valid'
+        }
+        const priceId = cryptoRandomString({ length: 10 })
+        const productId = cryptoRandomString({ length: 10 })
+        const roleCount = 10
+
+        let reconciledSubscriptionData: SubscriptionDataInput | undefined = undefined
+        const addWorkspaceSubscriptionSeatIfNeeded =
+          addWorkspaceSubscriptionSeatIfNeededFactory({
+            getWorkspacePlan: async () => workspacePlan,
+            getWorkspaceSubscription: async () => workspaceSubscription,
+            countWorkspaceRole: async ({ workspaceRole }) => {
+              switch (workspaceRole) {
+                case 'workspace:admin':
+                case 'workspace:member':
+                  return roleCount
+                case 'workspace:guest':
+                  expect.fail()
+              }
+            },
+            getWorkspacePlanPrice: ({ workspacePlan, billingInterval }) => {
+              if (billingInterval !== workspaceSubscription.billingInterval)
+                expect.fail()
+              switch (workspacePlan) {
+                case 'business':
+                case 'pro':
+                case 'guest':
+                  expect.fail()
+                case 'team':
+                  return priceId
+                default:
+                  throwUncoveredError(workspacePlan)
+              }
+            },
+            getWorkspacePlanProductId: (args) => {
+              if (args.workspacePlan !== workspacePlan.name) expect.fail()
+              return productId
+            },
+            reconcileSubscriptionData: async ({
+              applyProrotation,
+              subscriptionData
+            }) => {
+              if (!applyProrotation) expect.fail()
+              reconciledSubscriptionData = subscriptionData
+            }
+          })
+        await addWorkspaceSubscriptionSeatIfNeeded({
+          workspaceId,
+          role
+        })
+        expect(reconciledSubscriptionData!.products).deep.equalInAnyOrder([
+          { productId, priceId, quantity: 2 * roleCount }
+        ])
+      })
+    )
+    it('updates the sub existing product quantity if the one matching the new role, does not have enough quantities', async () => {
+      const workspaceId = cryptoRandomString({ length: 10 })
+
+      const priceId = cryptoRandomString({ length: 10 })
+      const productId = cryptoRandomString({ length: 10 })
+      const subscriptionItemId = cryptoRandomString({ length: 10 })
+      const subscriptionData = createTestSubscriptionData({
+        products: [
+          {
+            priceId,
+            productId,
+            quantity: 4,
+            subscriptionItemId
+          }
+        ]
+      })
+      const workspaceSubscription = createTestWorkspaceSubscription({
+        workspaceId,
+        subscriptionData
+      })
+      const workspacePlan: WorkspacePlan = {
+        name: 'team',
+        workspaceId,
+        status: 'valid'
+      }
+      const roleCount = 10
+
+      let reconciledSubscriptionData: SubscriptionDataInput | undefined = undefined
+      const addWorkspaceSubscriptionSeatIfNeeded =
+        addWorkspaceSubscriptionSeatIfNeededFactory({
+          getWorkspacePlan: async () => workspacePlan,
+          getWorkspaceSubscription: async () => workspaceSubscription,
+          countWorkspaceRole: async ({ workspaceRole }) => {
+            switch (workspaceRole) {
+              case 'workspace:admin':
+              case 'workspace:member':
+                return roleCount
+              case 'workspace:guest':
+                expect.fail()
+            }
+          },
+          getWorkspacePlanPrice: ({ workspacePlan, billingInterval }) => {
+            if (billingInterval !== workspaceSubscription.billingInterval) expect.fail()
+            switch (workspacePlan) {
+              case 'business':
+              case 'pro':
+              case 'guest':
+                expect.fail()
+              case 'team':
+                return priceId
+              default:
+                throwUncoveredError(workspacePlan)
+            }
+          },
+          getWorkspacePlanProductId: (args) => {
+            if (args.workspacePlan !== workspacePlan.name) expect.fail()
+            return productId
+          },
+          reconcileSubscriptionData: async ({ applyProrotation, subscriptionData }) => {
+            if (!applyProrotation) expect.fail()
+            reconciledSubscriptionData = subscriptionData
+          }
+        })
+      await addWorkspaceSubscriptionSeatIfNeeded({
+        workspaceId,
+        role: 'workspace:member'
+      })
+      expect(reconciledSubscriptionData!.products).deep.equalInAnyOrder([
+        { productId, priceId, quantity: 2 * roleCount, subscriptionItemId }
+      ])
+    })
+    it('does not update the subscription if the product matching the new role, has enough quantities', async () => {
+      const workspaceId = cryptoRandomString({ length: 10 })
+
+      const priceId = cryptoRandomString({ length: 10 })
+      const productId = cryptoRandomString({ length: 10 })
+      const subscriptionItemId = cryptoRandomString({ length: 10 })
+      const subscriptionData = createTestSubscriptionData({
+        products: [
+          {
+            priceId,
+            productId,
+            quantity: 2,
+            subscriptionItemId
+          }
+        ]
+      })
+      const workspaceSubscription = createTestWorkspaceSubscription({
+        workspaceId,
+        subscriptionData
+      })
+      const workspacePlan: WorkspacePlan = {
+        name: 'team',
+        workspaceId,
+        status: 'valid'
+      }
+      const roleCount = 1
+
+      const addWorkspaceSubscriptionSeatIfNeeded =
+        addWorkspaceSubscriptionSeatIfNeededFactory({
+          getWorkspacePlan: async () => workspacePlan,
+          getWorkspaceSubscription: async () => workspaceSubscription,
+          countWorkspaceRole: async ({ workspaceRole }) => {
+            switch (workspaceRole) {
+              case 'workspace:admin':
+              case 'workspace:member':
+                return roleCount
+              case 'workspace:guest':
+                expect.fail()
+            }
+          },
+          getWorkspacePlanPrice: ({ workspacePlan, billingInterval }) => {
+            if (billingInterval !== workspaceSubscription.billingInterval) expect.fail()
+            switch (workspacePlan) {
+              case 'business':
+              case 'pro':
+              case 'guest':
+                expect.fail()
+              case 'team':
+                return priceId
+              default:
+                throwUncoveredError(workspacePlan)
+            }
+          },
+          getWorkspacePlanProductId: (args) => {
+            if (args.workspacePlan !== workspacePlan.name) expect.fail()
+            return productId
+          },
+          reconcileSubscriptionData: async () => {
+            expect.fail()
+          }
+        })
+      await addWorkspaceSubscriptionSeatIfNeeded({
+        workspaceId,
+        role: 'workspace:member'
+      })
+    })
+  })
 })
diff --git a/workspace.code-workspace b/workspace.code-workspace
index 75d24d382..48902a487 100644
--- a/workspace.code-workspace
+++ b/workspace.code-workspace
@@ -97,7 +97,8 @@
       "Encryptor",
       "Insertable",
       "mjml",
-      "OIDC"
+      "OIDC",
+      "Prorotation"
     ],
     "tailwindCSS.experimental.configFile": {
       "packages/frontend-2/tailwind.config.mjs": "packages/frontend-2/**"