diff --git a/changelogs/unreleased/88244.json b/changelogs/unreleased/88244.json
new file mode 100644
index 0000000000..1b13ac5f87
--- /dev/null
+++ b/changelogs/unreleased/88244.json
@@ -0,0 +1,5 @@
+{
+  "title": "Opportunity form: make contact and partner fields mutually dependent",
+  "type": "fix",
+  "packages": "crm"
+}
diff --git a/packages/apps/crm/src/models/forms.ts b/packages/apps/crm/src/models/forms.ts
index 07ff0afe4c..adb841dba0 100644
--- a/packages/apps/crm/src/models/forms.ts
+++ b/packages/apps/crm/src/models/forms.ts
@@ -302,6 +302,11 @@ export const crm_formsRegister: FormConfigs = {
         widget: 'custom',
         customComponent: ClientProspectSearchBar,
         required: true,
+        dependsOn: {
+          contact: ({newValue}) => {
+            return newValue?.mainPartner;
+          },
+        },
       },
       contact: {
         titleKey: 'Crm_Contact',
@@ -311,7 +316,7 @@ export const crm_formsRegister: FormConfigs = {
         options: {
           showTitle: true,
         },
-        required: true,
+        requiredIf: ({objectState}) => objectState.partner == null,
       },
       expectedCloseDate: {
         titleKey: 'Crm_Opportunity_ExpectedCloseDate',