diff --git a/demo/demo.ts b/demo/demo.ts
index 729b712..862fa6a 100644
--- a/demo/demo.ts
+++ b/demo/demo.ts
@@ -58,7 +58,7 @@ async function showResponse(statusEl: Element | null, promise: Promise<any>) {
   }
 }
 
-function setupForm(selector: string, listener: () => Promise<any>) {
+function setupForm(selector: string, listener: (event: Event) => Promise<any>) {
   const formEl = document.querySelector<HTMLFormElement>(selector);
   if (!formEl) throw new Error(`No existe el formulario ${selector}`);
   const statusEl = formEl.querySelector<HTMLElement>(".status");
@@ -68,7 +68,7 @@ function setupForm(selector: string, listener: () => Promise<any>) {
     );
   formEl.addEventListener("submit", async (event) => {
     event.preventDefault();
-    showResponse(statusEl, listener());
+    showResponse(statusEl, listener(event));
   });
 }
 
@@ -78,5 +78,7 @@ setupForm("#save-token", async () => {
 });
 setupForm("#productos", () => getProductos(token(), {}));
 setupForm("#price", () => getPrices(token(), {}));
-setupForm("#price-by-customer", () => getPricesByCustomer(token(), {}));
+setupForm("#price-by-customer", (event) =>
+  getPricesByCustomer(token(), { filter: (event.target! as any).filter.value })
+);
 setupForm("#customer", () => getCustomers(token(), {}));
diff --git a/demo/index.html b/demo/index.html
index 1e9b66a..d6e8e26 100644
--- a/demo/index.html
+++ b/demo/index.html
@@ -45,6 +45,7 @@
 
 <form id="price-by-customer">
   <button>Conseguir precios by customer</button>
+  <input name="filter" type="text" placeholder="Filtro por ID (opcional)" />
   <p class="status"></p>
 </form>
 
diff --git a/priceByCustomer.ts b/priceByCustomer.ts
index c8e012a..052fc8a 100644
--- a/priceByCustomer.ts
+++ b/priceByCustomer.ts
@@ -7,6 +7,8 @@ import {
 
 export interface PriceByCustomerQuery {
   paginacion?: Paginacion;
+  /// Filtro por el código del cliente ("Code" en Customer.)
+  filter?: string;
 }
 
 export interface Precio {
@@ -27,6 +29,9 @@ export async function getPricesByCustomer(
 ): Promise<PreciosResponse> {
   let searchParams = new URLSearchParams();
   paginacionToSearchParams(options.paginacion, searchParams);
+  if (options.filter) {
+    searchParams.set("filter", options.filter);
+  }
   const res = await fetch(
     `${HOST}/api/Aperture/PriceByCustomer?${searchParams.toString()}`,
     {