diff --git a/src/lib/forms-shared.ts b/src/lib/forms-shared.ts
index b3c2d44..79a51a5 100644
--- a/src/lib/forms-shared.ts
+++ b/src/lib/forms-shared.ts
@@ -78,9 +78,29 @@ export const SYSTEM_VARIABLES = [
   { key: "{{firmName}}", description: "Your firm name" },
 ] as const;
 
+export interface CustomFieldVar {
+  key: string;
+  label: string;
+  description: string | null;
+}
+
+export async function fetchCustomFieldDefs(): Promise<CustomFieldVar[]> {
+  const { data } = await supabase
+    .from("custom_case_fields")
+    .select("key,label,description")
+    .eq("active", true)
+    .order("sort_order");
+  return (data ?? []) as CustomFieldVar[];
+}
+
 export function applyVariables(
   body: string,
-  ctx: { client?: ClientLite | null; homeowner?: HomeownerLite | null; firmName?: string },
+  ctx: {
+    client?: ClientLite | null;
+    homeowner?: HomeownerLite | null;
+    firmName?: string;
+    customValues?: Record<string, string>;
+  },
 ): string {
   const today = format(new Date(), "MMMM d, yyyy");
   const replacements: Record<string, string> = {
@@ -97,6 +117,12 @@ export function applyVariables(
   for (const [k, v] of Object.entries(replacements)) {
     out = out.split(k).join(v);
   }
+  // Custom variables like {{custom.mortgage_holder}}
+  if (ctx.customValues) {
+    for (const [k, v] of Object.entries(ctx.customValues)) {
+      out = out.split(`{{custom.${k}}}`).join(v ?? "");
+    }
+  }
   return out;
 }
 
diff --git a/src/routeTree.gen.ts b/src/routeTree.gen.ts
index f509e07..f44751d 100644
--- a/src/routeTree.gen.ts
+++ b/src/routeTree.gen.ts
@@ -34,6 +34,7 @@ import { Route as SettingsProfileRouteImport } from './routes/settings.profile'
 import { Route as SettingsImportRouteImport } from './routes/settings.import'
 import { Route as SettingsImapRouteImport } from './routes/settings.imap'
 import { Route as SettingsFeesRouteImport } from './routes/settings.fees'
+import { Route as SettingsCustomFieldsRouteImport } from './routes/settings.custom-fields'
 import { Route as InvoicesInvoiceIdRouteImport } from './routes/invoices.$invoiceId'
 import { Route as HooksPollImapRouteImport } from './routes/hooks/poll-imap'
 import { Route as ContactsContactIdRouteImport } from './routes/contacts.$contactId'
@@ -172,6 +173,11 @@ const SettingsFeesRoute = SettingsFeesRouteImport.update({
   path: '/fees',
   getParentRoute: () => SettingsRoute,
 } as any)
+const SettingsCustomFieldsRoute = SettingsCustomFieldsRouteImport.update({
+  id: '/custom-fields',
+  path: '/custom-fields',
+  getParentRoute: () => SettingsRoute,
+} as any)
 const InvoicesInvoiceIdRoute = InvoicesInvoiceIdRouteImport.update({
   id: '/invoices/$invoiceId',
   path: '/invoices/$invoiceId',
@@ -247,6 +253,7 @@ export interface FileRoutesByFullPath {
   '/contacts/$contactId': typeof ContactsContactIdRoute
   '/hooks/poll-imap': typeof HooksPollImapRoute
   '/invoices/$invoiceId': typeof InvoicesInvoiceIdRoute
+  '/settings/custom-fields': typeof SettingsCustomFieldsRoute
   '/settings/fees': typeof SettingsFeesRoute
   '/settings/imap': typeof SettingsImapRoute
   '/settings/import': typeof SettingsImportRoute
@@ -285,6 +292,7 @@ export interface FileRoutesByTo {
   '/contacts/$contactId': typeof ContactsContactIdRoute
   '/hooks/poll-imap': typeof HooksPollImapRoute
   '/invoices/$invoiceId': typeof InvoicesInvoiceIdRoute
+  '/settings/custom-fields': typeof SettingsCustomFieldsRoute
   '/settings/fees': typeof SettingsFeesRoute
   '/settings/imap': typeof SettingsImapRoute
   '/settings/import': typeof SettingsImportRoute
@@ -325,6 +333,7 @@ export interface FileRoutesById {
   '/contacts/$contactId': typeof ContactsContactIdRoute
   '/hooks/poll-imap': typeof HooksPollImapRoute
   '/invoices/$invoiceId': typeof InvoicesInvoiceIdRoute
+  '/settings/custom-fields': typeof SettingsCustomFieldsRoute
   '/settings/fees': typeof SettingsFeesRoute
   '/settings/imap': typeof SettingsImapRoute
   '/settings/import': typeof SettingsImportRoute
@@ -366,6 +375,7 @@ export interface FileRouteTypes {
     | '/contacts/$contactId'
     | '/hooks/poll-imap'
     | '/invoices/$invoiceId'
+    | '/settings/custom-fields'
     | '/settings/fees'
     | '/settings/imap'
     | '/settings/import'
@@ -404,6 +414,7 @@ export interface FileRouteTypes {
     | '/contacts/$contactId'
     | '/hooks/poll-imap'
     | '/invoices/$invoiceId'
+    | '/settings/custom-fields'
     | '/settings/fees'
     | '/settings/imap'
     | '/settings/import'
@@ -443,6 +454,7 @@ export interface FileRouteTypes {
     | '/contacts/$contactId'
     | '/hooks/poll-imap'
     | '/invoices/$invoiceId'
+    | '/settings/custom-fields'
     | '/settings/fees'
     | '/settings/imap'
     | '/settings/import'
@@ -679,6 +691,13 @@ declare module '@tanstack/react-router' {
       preLoaderRoute: typeof SettingsFeesRouteImport
       parentRoute: typeof SettingsRoute
     }
+    '/settings/custom-fields': {
+      id: '/settings/custom-fields'
+      path: '/custom-fields'
+      fullPath: '/settings/custom-fields'
+      preLoaderRoute: typeof SettingsCustomFieldsRouteImport
+      parentRoute: typeof SettingsRoute
+    }
     '/invoices/$invoiceId': {
       id: '/invoices/$invoiceId'
       path: '/invoices/$invoiceId'
@@ -767,6 +786,7 @@ declare module '@tanstack/react-router' {
 }
 
 interface SettingsRouteChildren {
+  SettingsCustomFieldsRoute: typeof SettingsCustomFieldsRoute
   SettingsFeesRoute: typeof SettingsFeesRoute
   SettingsImapRoute: typeof SettingsImapRoute
   SettingsImportRoute: typeof SettingsImportRoute
@@ -778,6 +798,7 @@ interface SettingsRouteChildren {
 }
 
 const SettingsRouteChildren: SettingsRouteChildren = {
+  SettingsCustomFieldsRoute: SettingsCustomFieldsRoute,
   SettingsFeesRoute: SettingsFeesRoute,
   SettingsImapRoute: SettingsImapRoute,
   SettingsImportRoute: SettingsImportRoute,