diff --git a/services/web/app/src/Features/Email/EmailBuilder.mjs b/services/web/app/src/Features/Email/EmailBuilder.mjs
index 751abf11c0..3cececcfcb 100644
--- a/services/web/app/src/Features/Email/EmailBuilder.mjs
+++ b/services/web/app/src/Features/Email/EmailBuilder.mjs
@@ -1023,6 +1023,36 @@ templates.taxExemptCertificateRequired = NoCTAEmailTemplate({
   },
 })
 
+templates.groupMemberLimitWarning = ctaTemplate({
+  subject(opts) {
+    return `${opts.groupName || 'Your group'} is approaching its member limit`
+  },
+  title(opts) {
+    return `${opts.groupName || 'Your group'} is approaching its member limit`
+  },
+  greeting(opts) {
+    return opts.firstName ? `Hi ${opts.firstName},` : 'Hi,'
+  },
+  message(opts) {
+    return [
+      `Your group "${opts.groupName}" is approaching its member limit.`,
+      `<b>Current usage:</b> ${opts.currentMembers} of ${opts.membersLimit} licenses used (${opts.remainingSeats} remaining)`,
+      'With domain capture enabled, users with verified email addresses from your domain can automatically join the group via SSO. Once the member limit is reached, new users will be blocked from joining.',
+    ]
+  },
+  secondaryMessage() {
+    return [
+      'To ensure uninterrupted access for your users, consider adding more licenses or removing inactive members.',
+    ]
+  },
+  ctaText() {
+    return 'Add licenses'
+  },
+  ctaURL() {
+    return `${settings.siteUrl}/user/subscription/group/add-users`
+  },
+})
+
 function _formatUserNameAndEmail(user, placeholder) {
   if (user.first_name && user.last_name) {
     const fullName = `${user.first_name} ${user.last_name}`
diff --git a/services/web/app/src/models/Subscription.mjs b/services/web/app/src/models/Subscription.mjs
index 74e6c1684d..9134541192 100644
--- a/services/web/app/src/models/Subscription.mjs
+++ b/services/web/app/src/models/Subscription.mjs
@@ -39,6 +39,7 @@ export const SubscriptionSchema = new Schema(
     domainCaptureEnabled: { type: Boolean, default: false },
     managedUsersEnabled: { type: Boolean, default: false },
     membersLimit: { type: Number, default: 0 },
+    membersLimitNotificationSent: { type: Boolean, default: false },
     customAccount: Boolean,
     features: {
       managedUsers: { type: Boolean, default: true },
diff --git a/services/web/test/unit/src/Email/EmailBuilder.test.mjs b/services/web/test/unit/src/Email/EmailBuilder.test.mjs
index 607a706530..9e010f57b9 100644
--- a/services/web/test/unit/src/Email/EmailBuilder.test.mjs
+++ b/services/web/test/unit/src/Email/EmailBuilder.test.mjs
@@ -976,6 +976,72 @@ describe('EmailBuilder', function () {
           })
         })
       })
+
+      describe('groupMemberLimitWarning', function () {
+        beforeEach(function (ctx) {
+          ctx.emailAddress = 'example@overleaf.com'
+          ctx.opts = {
+            to: ctx.emailAddress,
+            groupName: 'Example Group',
+            firstName: 'Joe',
+            currentMembers: 9,
+            membersLimit: 10,
+            remainingSeats: 1,
+          }
+          ctx.email = ctx.EmailBuilder.buildEmail(
+            'groupMemberLimitWarning',
+            ctx.opts
+          )
+          ctx.expectedUrl = `${ctx.settings.siteUrl}/user/subscription/group/add-users`
+        })
+
+        it('should build the email', function (ctx) {
+          expect(ctx.email.html).to.exist
+          expect(ctx.email.text).to.exist
+        })
+
+        describe('HTML email', function () {
+          it('should include a CTA button and a fallback CTA link', function (ctx) {
+            const dom = cheerio.load(ctx.email.html)
+            const plainText = dom.text()
+            expect(ctx.email.subject).to.equal(
+              `${ctx.opts.groupName} is approaching its member limit`
+            )
+            expect(ctx.email.html).to.exist
+            expect(ctx.email.html).to.contain(
+              `Your group "${ctx.opts.groupName}" is approaching its member limit.`
+            )
+            expect(plainText).to.contain(
+              `Current usage: ${ctx.opts.currentMembers} of ` +
+                `${ctx.opts.membersLimit} licenses used ` +
+                `(${ctx.opts.remainingSeats} remaining)`
+            )
+            expect(ctx.email.html).to.contain(
+              'With domain capture enabled, users with verified email ' +
+                'addresses from your domain can automatically join the group ' +
+                'via SSO. Once the member limit is reached, new users will ' +
+                'be blocked from joining.'
+            )
+            expect(ctx.email.html).to.contain(
+              'To ensure uninterrupted access for your users, consider ' +
+                'adding more licenses or removing inactive members.'
+            )
+            const buttonLink = dom('td a')
+            expect(buttonLink).to.exist
+            expect(buttonLink.attr('href')).to.equal(ctx.expectedUrl)
+            const fallback = dom('.force-overleaf-style').last()
+            expect(fallback).to.exist
+            const fallbackLink = fallback.html().replace(/&amp;/g, '&')
+            expect(fallbackLink).to.contain(ctx.expectedUrl)
+          })
+        })
+
+        describe('plain text email', function () {
+          it('should contain the CTA link', function (ctx) {
+            expect(ctx.email.text).to.contain(ctx.expectedUrl)
+          })
+        })
+      })
     })
   })
 })