diff --git a/modules/ask_va_api/app/controllers/ask_va_api/v0/inquiries_controller.rb b/modules/ask_va_api/app/controllers/ask_va_api/v0/inquiries_controller.rb
index 12860b01335..5297fbb74c5 100644
--- a/modules/ask_va_api/app/controllers/ask_va_api/v0/inquiries_controller.rb
+++ b/modules/ask_va_api/app/controllers/ask_va_api/v0/inquiries_controller.rb
@@ -109,13 +109,13 @@ def require_loa3!
         raise Common::Exceptions::Unauthorized unless current_user&.loa&.fetch(:current, nil) == 3
       end
 
-      INQUIRY_ID_FORMAT = /\AA-[0-9]{8}-[0-9]{6,7}\z/
+      INQUIRY_ID_FORMAT = /\AA-[0-9]{8}-[0-9]{5,10}\z/
 
-      # Validates that params[:id] follows the known inquiry ID format "A-YYYYMMDD-NNNNNN".
+      # Validates that params[:id] follows the known inquiry ID format "A-<8-digit date>-<5-10 digit number>".
       def validate_inquiry_id_format
-        unless params[:id].match?(INQUIRY_ID_FORMAT)
-          render json: { error: 'Invalid inquiry ID format. Expected format: A-YYYYMMDD-NNNNNN.' }, status: :bad_request
-        end
+        msg = 'Invalid inquiry ID format. Expected: A-<8-digit date>-<5-10 digit number> (e.g., A-20260416-1234567).'
+
+        render json: { error: msg }, status: :bad_request unless params[:id].match?(INQUIRY_ID_FORMAT)
       end
 
       class InvalidAttachmentError < StandardError; end
diff --git a/modules/ask_va_api/spec/requests/ask_va_api/v0/inquiries_spec.rb b/modules/ask_va_api/spec/requests/ask_va_api/v0/inquiries_spec.rb
index 757f2685d4c..c3795295665 100644
--- a/modules/ask_va_api/spec/requests/ask_va_api/v0/inquiries_spec.rb
+++ b/modules/ask_va_api/spec/requests/ask_va_api/v0/inquiries_spec.rb
@@ -491,7 +491,8 @@
     end
 
     context 'when the id format is invalid' do
-      %w[invalid 12345 A-1234567-123456 A-12345678-12345 A-12345678-12345678 A12345678123456].each do |bad_id|
+      %w[invalid 12345 A-1234567-123456 A-12345678-1234 A-12345678-12345678901 A-12345678-12L4567
+         A12345678123456].each do |bad_id|
         it "returns bad_request for '#{bad_id}'" do
           get "/ask_va_api/v0/inquiries/#{bad_id}/status"
           expect(response).to have_http_status(:bad_request)