diff --git a/src/schemas/invoices.schema.ts b/src/schemas/invoices.schema.ts
index b6ae94f..dccfebc 100644
--- a/src/schemas/invoices.schema.ts
+++ b/src/schemas/invoices.schema.ts
@@ -53,7 +53,7 @@ export const CreateInvoiceSchema = z.object({
   // Positional indices of company custom fields to print on this document's PDF.
   selected_custom_fields: z
     .array(z.number().int().nonnegative())
-    .max(200)
+    .max(50)
     .optional(),
 });
 
@@ -81,7 +81,7 @@ export const UpdateInvoiceSchema = z.object({
   sections: z.array(DocumentSectionSchema).optional(),
   selected_custom_fields: z
     .array(z.number().int().nonnegative())
-    .max(200)
+    .max(50)
     .optional(),
 });
 
diff --git a/src/schemas/issued-orders.schema.ts b/src/schemas/issued-orders.schema.ts
index f570c47..e137f5f 100644
--- a/src/schemas/issued-orders.schema.ts
+++ b/src/schemas/issued-orders.schema.ts
@@ -45,7 +45,7 @@ export const CreateIssuedOrderSchema = z.object({
   // PDF. Omitted/empty ⇒ none. Update schema derives via .partial().
   selected_custom_fields: z
     .array(z.number().int().nonnegative())
-    .max(200)
+    .max(50)
     .optional(),
 });
 
diff --git a/src/schemas/offers.schema.ts b/src/schemas/offers.schema.ts
index 5a52677..427b94f 100644
--- a/src/schemas/offers.schema.ts
+++ b/src/schemas/offers.schema.ts
@@ -52,7 +52,7 @@ export const CreateQuotationSchema = z.object({
   // PDF. Omitted/empty ⇒ none. Update schema derives via .partial().
   selected_custom_fields: z
     .array(z.number().int().nonnegative())
-    .max(200)
+    .max(50)
     .optional(),
 });
 
diff --git a/src/services/issued-orders.service.ts b/src/services/issued-orders.service.ts
index 4265942..7925e2c 100644
--- a/src/services/issued-orders.service.ts
+++ b/src/services/issued-orders.service.ts
@@ -129,6 +129,7 @@ const NON_STATUS_UPDATE_FIELDS = [
   "language",
   "order_text",
   "internal_notes",
+  "selected_custom_fields",
   "items",
   "sections",
 ] as const;
diff --git a/src/services/offers.service.ts b/src/services/offers.service.ts
index 3842a3e..a244c3f 100644
--- a/src/services/offers.service.ts
+++ b/src/services/offers.service.ts
@@ -68,6 +68,7 @@ const NON_STATUS_UPDATE_FIELDS = [
   "language",
   "scope_title",
   "scope_description",
+  "selected_custom_fields",
   "items",
   "sections",
 ] as const;