diff --git a/apps/www/app/api-v2/submit-form-security-newsletter/route.tsx b/apps/www/app/api-v2/submit-form-security-newsletter/route.tsx
index 3e4d9ab8d71..9c45dc060f6 100644
--- a/apps/www/app/api-v2/submit-form-security-newsletter/route.tsx
+++ b/apps/www/app/api-v2/submit-form-security-newsletter/route.tsx
@@ -1,6 +1,6 @@
 import * as Sentry from '@sentry/nextjs'
-
 import { CustomerioTrackClient } from '~/lib/customerio'
+import { createRateLimiter } from '~/lib/rate-limit'
 
 const corsHeaders = {
   'Access-Control-Allow-Origin': '*',
@@ -12,7 +12,16 @@ const isValidEmail = (email: string): boolean => {
   return emailPattern.test(email)
 }
 
+const isRateLimited = createRateLimiter({ max: 5, windowMs: 60 * 1000 })
+
 export async function POST(req: Request) {
+  if (isRateLimited(req)) {
+    return new Response(JSON.stringify({ message: 'Too many requests. Try again later.' }), {
+      headers: { ...corsHeaders, 'Content-Type': 'application/json' },
+      status: 429,
+    })
+  }
+
   const body = await req.json()
   const { firstName, lastName, email } = body
 
diff --git a/apps/www/app/api-v2/submit-form-subprocessor-updates/route.test.ts b/apps/www/app/api-v2/submit-form-subprocessor-updates/route.test.ts
new file mode 100644
index 00000000000..c8597164367
--- /dev/null
+++ b/apps/www/app/api-v2/submit-form-subprocessor-updates/route.test.ts
@@ -0,0 +1,29 @@
+import { describe, expect, it, vi } from 'vitest'
+
+import { POST } from './route'
+
+vi.mock('server-only', () => ({}))
+vi.mock('@sentry/nextjs', () => ({ captureException: vi.fn() }))
+
+const makeRequest = (ip: string) =>
+  new Request('http://localhost/api-v2/submit-form-subprocessor-updates', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json', 'x-forwarded-for': ip },
+    body: JSON.stringify({}),
+  })
+
+describe('submit-form-subprocessor-updates rate limiting', () => {
+  it('returns 429 on the sixth request in a window from one ip', async () => {
+    for (let i = 0; i < 5; i++) {
+      const res = await POST(makeRequest('203.0.113.7'))
+      expect(res.status).toBe(422)
+    }
+    const res = await POST(makeRequest('203.0.113.7'))
+    expect(res.status).toBe(429)
+  })
+
+  it('does not rate limit a different ip', async () => {
+    const res = await POST(makeRequest('203.0.113.8'))
+    expect(res.status).toBe(422)
+  })
+})
diff --git a/apps/www/app/api-v2/submit-form-subprocessor-updates/route.tsx b/apps/www/app/api-v2/submit-form-subprocessor-updates/route.tsx
index b9128e6e174..284b15c2852 100644
--- a/apps/www/app/api-v2/submit-form-subprocessor-updates/route.tsx
+++ b/apps/www/app/api-v2/submit-form-subprocessor-updates/route.tsx
@@ -1,6 +1,6 @@
 import * as Sentry from '@sentry/nextjs'
-
 import { CustomerioTrackClient } from '~/lib/customerio'
+import { createRateLimiter } from '~/lib/rate-limit'
 
 const corsHeaders = {
   'Access-Control-Allow-Origin': '*',
@@ -12,7 +12,16 @@ const isValidEmail = (email: string): boolean => {
   return emailPattern.test(email)
 }
 
+const isRateLimited = createRateLimiter({ max: 5, windowMs: 60 * 1000 })
+
 export async function POST(req: Request) {
+  if (isRateLimited(req)) {
+    return new Response(JSON.stringify({ message: 'Too many requests. Try again later.' }), {
+      headers: { ...corsHeaders, 'Content-Type': 'application/json' },
+      status: 429,
+    })
+  }
+
   const body = await req.json()
   const { firstName, lastName, email } = body