diff --git a/packages/twenty-website/src/app/[locale]/(focused)/partners/brief/ClientBriefPageContent.tsx b/packages/twenty-website/src/app/[locale]/(focused)/partners/brief/ClientBriefPageContent.tsx
index 738ea3e644..cf5c6a6cd1 100644
--- a/packages/twenty-website/src/app/[locale]/(focused)/partners/brief/ClientBriefPageContent.tsx
+++ b/packages/twenty-website/src/app/[locale]/(focused)/partners/brief/ClientBriefPageContent.tsx
@@ -25,11 +25,15 @@ const BriefContainer = styled.div`
   }
 `;
 
-export function ClientBriefPageContent() {
+export function ClientBriefPageContent({
+  partnerSlug,
+}: {
+  partnerSlug?: string;
+}) {
   return (
     <BriefBackground data-scheme="dark">
       <BriefContainer>
-        <ClientBriefWizard />
+        <ClientBriefWizard partnerSlug={partnerSlug} />
       </BriefContainer>
     </BriefBackground>
   );
diff --git a/packages/twenty-website/src/app/[locale]/(focused)/partners/brief/page.tsx b/packages/twenty-website/src/app/[locale]/(focused)/partners/brief/page.tsx
index 3b3c15f78d..28c101c2f5 100644
--- a/packages/twenty-website/src/app/[locale]/(focused)/partners/brief/page.tsx
+++ b/packages/twenty-website/src/app/[locale]/(focused)/partners/brief/page.tsx
@@ -1,3 +1,4 @@
+import { normalizePartnerSlug } from '@/client-brief/normalize-partner-slug';
 import {
   getRouteI18n,
   type LocaleRouteParams,
@@ -10,10 +11,13 @@ export const generateMetadata = buildRouteMetadata('partnersBrief');
 
 export default async function ClientBriefPage({
   params,
+  searchParams,
 }: {
   params: Promise<LocaleRouteParams>;
+  searchParams: Promise<{ partner?: string | string[] }>;
 }) {
   await getRouteI18n(params);
+  const { partner } = await searchParams;
 
-  return <ClientBriefPageContent />;
+  return <ClientBriefPageContent partnerSlug={normalizePartnerSlug(partner)} />;
 }
diff --git a/packages/twenty-website/src/client-brief/build-client-brief-request-body.test.ts b/packages/twenty-website/src/client-brief/build-client-brief-request-body.test.ts
new file mode 100644
index 0000000000..95a60f764a
--- /dev/null
+++ b/packages/twenty-website/src/client-brief/build-client-brief-request-body.test.ts
@@ -0,0 +1,23 @@
+import { buildClientBriefRequestBody } from './build-client-brief-request-body';
+import { INITIAL_CLIENT_BRIEF_STATE } from './client-brief-state';
+
+const state = {
+  ...INITIAL_CLIENT_BRIEF_STATE,
+  firstName: 'Jane',
+  lastName: 'Smith',
+  email: 'jane@acme.com',
+  companyName: 'Acme Real Estate',
+  need: 'Migrate from HubSpot',
+};
+
+describe('buildClientBriefRequestBody', () => {
+  it('puts the referring partner slug on the wire', () => {
+    expect(
+      buildClientBriefRequestBody(state, 'acme-consulting').partnerSlug,
+    ).toBe('acme-consulting');
+  });
+
+  it('omits the key entirely when no slug is given', () => {
+    expect('partnerSlug' in buildClientBriefRequestBody(state)).toBe(false);
+  });
+});
diff --git a/packages/twenty-website/src/client-brief/build-client-brief-request-body.ts b/packages/twenty-website/src/client-brief/build-client-brief-request-body.ts
index e2058e6f19..c4dccfd6cd 100644
--- a/packages/twenty-website/src/client-brief/build-client-brief-request-body.ts
+++ b/packages/twenty-website/src/client-brief/build-client-brief-request-body.ts
@@ -10,6 +10,7 @@ function splitLanguages(value: string): string[] {
 
 export function buildClientBriefRequestBody(
   state: ClientBriefState,
+  partnerSlug?: string,
 ): ClientBriefRequest {
   const body: ClientBriefRequest = {
     firstName: state.firstName.trim(),
@@ -27,6 +28,7 @@ export function buildClientBriefRequestBody(
   if (state.seatCount.trim()) body.seatCount = state.seatCount.trim();
   if (state.timeline.trim()) body.timeline = state.timeline.trim();
   if (state.budgetRange.trim()) body.budgetRange = state.budgetRange.trim();
+  if (partnerSlug) body.partnerSlug = partnerSlug;
 
   return body;
 }
diff --git a/packages/twenty-website/src/client-brief/client-brief-request-schema.test.ts b/packages/twenty-website/src/client-brief/client-brief-request-schema.test.ts
index 2f5ca6e0e4..53dd429305 100644
--- a/packages/twenty-website/src/client-brief/client-brief-request-schema.test.ts
+++ b/packages/twenty-website/src/client-brief/client-brief-request-schema.test.ts
@@ -68,4 +68,22 @@ describe('clientBriefRequestSchema', () => {
         .success,
     ).toBe(false);
   });
+
+  it('accepts a payload carrying a referring partner slug', () => {
+    expect(
+      clientBriefRequestSchema.safeParse({
+        ...minimalValid,
+        partnerSlug: 'acme-consulting',
+      }).success,
+    ).toBe(true);
+  });
+
+  it('rejects a malformed partner slug', () => {
+    expect(
+      clientBriefRequestSchema.safeParse({
+        ...minimalValid,
+        partnerSlug: 'Acme Consulting!',
+      }).success,
+    ).toBe(false);
+  });
 });
diff --git a/packages/twenty-website/src/client-brief/client-brief-request-schema.ts b/packages/twenty-website/src/client-brief/client-brief-request-schema.ts
index 844850c199..be7ab9fca8 100644
--- a/packages/twenty-website/src/client-brief/client-brief-request-schema.ts
+++ b/packages/twenty-website/src/client-brief/client-brief-request-schema.ts
@@ -3,6 +3,7 @@ import { z } from 'zod';
 import { emailFieldSchema } from '@/partner-application/email-field-schema';
 
 import { CLIENT_BRIEF_HOSTING_TYPES } from './data/hosting-type-values';
+import { partnerSlugSchema } from './partner-slug-schema';
 
 const optionalNonEmptyString = z.string().trim().min(1).optional();
 
@@ -19,6 +20,7 @@ export const clientBriefRequestSchema = z.strictObject({
   seatCount: optionalNonEmptyString,
   timeline: optionalNonEmptyString,
   budgetRange: optionalNonEmptyString,
+  partnerSlug: partnerSlugSchema.optional(),
 });
 
 export type ClientBriefRequest = z.infer<typeof clientBriefRequestSchema>;
diff --git a/packages/twenty-website/src/client-brief/normalize-partner-slug.test.ts b/packages/twenty-website/src/client-brief/normalize-partner-slug.test.ts
new file mode 100644
index 0000000000..a85bf6abc6
--- /dev/null
+++ b/packages/twenty-website/src/client-brief/normalize-partner-slug.test.ts
@@ -0,0 +1,29 @@
+import { normalizePartnerSlug } from './normalize-partner-slug';
+
+describe('normalizePartnerSlug', () => {
+  it('returns a well-formed slug unchanged', () => {
+    expect(normalizePartnerSlug('acme-consulting')).toBe('acme-consulting');
+  });
+
+  it('returns undefined when the param is absent', () => {
+    expect(normalizePartnerSlug(undefined)).toBeUndefined();
+  });
+
+  it('returns undefined for an empty string', () => {
+    expect(normalizePartnerSlug('')).toBeUndefined();
+  });
+
+  it('drops a slug with unsupported characters instead of forwarding it', () => {
+    expect(normalizePartnerSlug('Acme Consulting!')).toBeUndefined();
+  });
+
+  it('drops an over-long slug', () => {
+    expect(normalizePartnerSlug('a'.repeat(101))).toBeUndefined();
+  });
+
+  it('takes the first value when the param is repeated', () => {
+    expect(normalizePartnerSlug(['acme-consulting', 'other'])).toBe(
+      'acme-consulting',
+    );
+  });
+});
diff --git a/packages/twenty-website/src/client-brief/normalize-partner-slug.ts b/packages/twenty-website/src/client-brief/normalize-partner-slug.ts
new file mode 100644
index 0000000000..0156aa7f2d
--- /dev/null
+++ b/packages/twenty-website/src/client-brief/normalize-partner-slug.ts
@@ -0,0 +1,9 @@
+import { partnerSlugSchema } from './partner-slug-schema';
+
+// The API schema is strict: a malformed value must be dropped here, not
+// forwarded, or it fails the whole brief submission.
+export function normalizePartnerSlug(
+  raw: string | string[] | undefined,
+): string | undefined {
+  return partnerSlugSchema.safeParse(Array.isArray(raw) ? raw[0] : raw).data;
+}
diff --git a/packages/twenty-website/src/client-brief/partner-slug-schema.ts b/packages/twenty-website/src/client-brief/partner-slug-schema.ts
new file mode 100644
index 0000000000..47f4bf2344
--- /dev/null
+++ b/packages/twenty-website/src/client-brief/partner-slug-schema.ts
@@ -0,0 +1,9 @@
+import { z } from 'zod';
+
+// Mirrors the backend `slugify` output. Shared by the request schema and
+// normalizePartnerSlug so the rule has one owner.
+export const partnerSlugSchema = z
+  .string()
+  .trim()
+  .regex(/^[a-z0-9-]+$/)
+  .max(100);
diff --git a/packages/twenty-website/src/client-brief/wizard/ClientBriefWizard.tsx b/packages/twenty-website/src/client-brief/wizard/ClientBriefWizard.tsx
index d947b0cbfc..004955c669 100644
--- a/packages/twenty-website/src/client-brief/wizard/ClientBriefWizard.tsx
+++ b/packages/twenty-website/src/client-brief/wizard/ClientBriefWizard.tsx
@@ -135,7 +135,7 @@ function StepRenderer({ controller }: { controller: ClientBriefController }) {
   }
 }
 
-export function ClientBriefWizard() {
+export function ClientBriefWizard({ partnerSlug }: { partnerSlug?: string }) {
   const { i18n } = useLingui();
   const controller = useClientBriefState();
   const {
@@ -176,7 +176,7 @@ export function ClientBriefWizard() {
         return;
       }
 
-      const payload = buildClientBriefRequestBody(state);
+      const payload = buildClientBriefRequestBody(state, partnerSlug);
       setSubmitting(true);
       try {
         const response = await fetch('/api/client-brief', {
@@ -199,6 +199,7 @@ export function ClientBriefWizard() {
       goNext,
       i18n,
       isLastStep,
+      partnerSlug,
       setFieldErrors,
       setSubmitError,
       setSubmitted,
diff --git a/packages/twenty-website/src/partners-marketplace/PartnerProfile.tsx b/packages/twenty-website/src/partners-marketplace/PartnerProfile.tsx
index 34bca7b141..0b5b7e40a3 100644
--- a/packages/twenty-website/src/partners-marketplace/PartnerProfile.tsx
+++ b/packages/twenty-website/src/partners-marketplace/PartnerProfile.tsx
@@ -144,6 +144,7 @@ export function PartnerProfile({ partner }: { partner: MarketplacePartner }) {
               calendarLink={partner.calendarLink}
               links={partner.links}
               linkUrls={partner.linkUrls}
+              slug={partner.slug}
             />
             <PartnerRatesPanel
               hourlyRateUsd={partner.hourlyRateUsd}
diff --git a/packages/twenty-website/src/partners-marketplace/PartnerProfileCtas.tsx b/packages/twenty-website/src/partners-marketplace/PartnerProfileCtas.tsx
index 6deb8cc9e2..370f33609b 100644
--- a/packages/twenty-website/src/partners-marketplace/PartnerProfileCtas.tsx
+++ b/packages/twenty-website/src/partners-marketplace/PartnerProfileCtas.tsx
@@ -118,10 +118,12 @@ export function PartnerProfileCtas({
   calendarLink,
   links,
   linkUrls,
+  slug,
 }: {
   calendarLink: string;
   links: PartnerLinks;
   linkUrls?: readonly string[];
+  slug: string;
 }) {
   const { i18n } = useLingui();
   const calendarHref = isSafeHttpUrl(calendarLink) ? calendarLink : null;
@@ -178,7 +180,7 @@ export function PartnerProfileCtas({
         )}
         <PrimaryAction>
           <Button
-            href="/partners/brief"
+            href={`/partners/brief?partner=${encodeURIComponent(slug)}`}
             label={i18n._(msg`Submit a brief`)}
             variant="outlined"
           />