diff --git a/src/app/api/portal/pagos-validados/route.ts b/src/app/api/portal/pagos-validados/route.ts
index 0fe5b6e..934a57e 100644
--- a/src/app/api/portal/pagos-validados/route.ts
+++ b/src/app/api/portal/pagos-validados/route.ts
@@ -18,11 +18,15 @@ export async function GET(req: Request): Promise<Response> {
     const year = url.searchParams.get("year") ?? String(now.getFullYear());
     const m = Number(mes);
     const y = Number(year);
+    const l = Number(url.searchParams.get("limite") ?? "200");
     if (!Number.isInteger(m) || m < 1 || m > 12 || !Number.isInteger(y) || y < 2000 || y > 2100) {
       return NextResponse.json({ error: "mes (1-12) y year válidos requeridos" }, { status: 400 });
     }
+    if (!Number.isInteger(l) || l < 1 || l > 1000) {
+      return NextResponse.json({ error: "limite (1-1000) requerido" }, { status: 400 });
+    }
     const res = await fetch(
-      `${SAM_API_URL}/api/Boletas/payments?mes=${m}&year=${y}`,
+      `${SAM_API_URL}/api/Boletas/payments?mes=${m}&year=${y}&limite=${l}`,
       { cache: "no-store" }
     );
     const text = await res.text();
diff --git a/src/app/m/[name]/page.tsx b/src/app/m/[name]/page.tsx
index f467928..2c0d22c 100644
--- a/src/app/m/[name]/page.tsx
+++ b/src/app/m/[name]/page.tsx
@@ -67,6 +67,18 @@ interface Boleta {
   monto: number;
   tipo?: string;
   estado?: string;
+  esValido?: boolean;
+  errorMotivo?: string | null;
+}
+
+// Fecha real = distinta de nula/vacía y del MinValue de .NET
+// (0001-01-01: la función PG no informó fecha de caja).
+function fechaReal(f: string | null | undefined): boolean {
+  return !!f && !f.startsWith("0001-01-01");
+}
+
+function fechaCorta(f: string | null | undefined): string {
+  return fechaReal(f) ? String(f).slice(0, 10) : "—";
 }
 
 function HelpdeskUsage() {
@@ -229,7 +241,7 @@ function PagosUsage() {
     setLoading(true);
     setError(null);
     try {
-      const res = await fetch(`/api/portal/pagos-validados?mes=${m}&year=${y}`, {
+      const res = await fetch(`/api/portal/pagos-validados?mes=${m}&year=${y}&limite=200`, {
         cache: "no-store",
       });
       const data = await res.json().catch(() => null);
@@ -254,7 +266,13 @@ function PagosUsage() {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, []);
 
-  const total = (rows ?? []).reduce((acc, r) => acc + (Number(r.monto) || 0), 0);
+  const valid = (rows ?? []).filter(
+    (r) => r.esValido !== false && fechaReal(r.fecha)
+  );
+  const errors = (rows ?? []).filter(
+    (r) => r.esValido === false || !fechaReal(r.fecha)
+  );
+  const total = valid.reduce((acc, r) => acc + (Number(r.monto) || 0), 0);
 
   return (
     <>
@@ -300,7 +318,9 @@ function PagosUsage() {
               </button>
               {rows && (
                 <span className="ms-auto small text-muted align-self-center">
-                  {rows.length} pagos · Total ${total.toLocaleString("es-CL")}
+                  {valid.length} válidos
+                  {errors.length > 0 && ` · ${errors.length} observados`} · Total
+                  ${total.toLocaleString("es-CL")}
                 </span>
               )}
             </form>
@@ -318,11 +338,11 @@ function PagosUsage() {
               </div>
             )}
 
-            {!error && !loading && rows && rows.length === 0 && (
-              <p className="text-muted mb-0">Sin pagos validados para {mes}/{year}.</p>
+            {!error && !loading && rows && valid.length === 0 && (
+              <p className="text-muted mb-0">Sin pagos válidos para {mes}/{year}.</p>
             )}
 
-            {!error && !loading && rows && rows.length > 0 && (
+            {!error && !loading && rows && valid.length > 0 && (
               <div className="table-responsive">
                 <table className="table table-sm table-hover mb-0">
                   <thead>
@@ -335,7 +355,7 @@ function PagosUsage() {
                     </tr>
                   </thead>
                   <tbody>
-                    {rows.slice(0, 100).map((r, i) => (
+                    {valid.slice(0, 100).map((r, i) => (
                       <tr key={`${r.folio}-${i}`}>
                         <td>{r.folio}</td>
                         <td className="small">
@@ -344,20 +364,60 @@ function PagosUsage() {
                             <span className="text-muted d-block">{r.alumnoRut}</span>
                           ) : null}
                         </td>
-                        <td className="small">
-                          {r.fecha ? String(r.fecha).slice(0, 10) : "—"}
-                        </td>
+                        <td className="small">{fechaCorta(r.fecha)}</td>
                         <td className="text-end">${Number(r.monto || 0).toLocaleString("es-CL")}</td>
                         <td className="small">{r.estado || r.tipo || "—"}</td>
                       </tr>
                     ))}
                   </tbody>
                 </table>
-                {rows.length > 100 && (
-                  <small className="text-muted">Mostrando 100 de {rows.length}.</small>
+                {valid.length > 100 && (
+                  <small className="text-muted">Mostrando 100 de {valid.length}.</small>
                 )}
               </div>
             )}
+            {!error && !loading && rows && errors.length > 0 && (
+              <details className="mt-3">
+                <summary className="small text-warning fw-semibold" style={{ cursor: "pointer" }}>
+                  <i className="bx bx-error me-1" />
+                  {errors.length} registro{errors.length !== 1 ? "s" : ""} observado{
+                    errors.length !== 1 ? "s" : ""
+                  } (no son ventas válidas)
+                </summary>
+                <div className="table-responsive mt-2">
+                  <table className="table table-sm table-hover mb-0">
+                    <thead>
+                      <tr>
+                        <th>Folio</th>
+                        <th>Alumno</th>
+                        <th>Fecha</th>
+                        <th className="text-end">Monto</th>
+                        <th>Motivo</th>
+                      </tr>
+                    </thead>
+                    <tbody>
+                      {errors.slice(0, 100).map((r, i) => (
+                        <tr key={`err-${r.folio}-${i}`}>
+                          <td>{r.folio || "—"}</td>
+                          <td className="small">
+                            {r.alumnoNombre ?? "—"}
+                            {r.alumnoRut ? (
+                              <span className="text-muted d-block">{r.alumnoRut}</span>
+                            ) : null}
+                          </td>
+                          <td className="small">{fechaCorta(r.fecha)}</td>
+                          <td className="text-end">${Number(r.monto || 0).toLocaleString("es-CL")}</td>
+                          <td className="small text-warning">{r.errorMotivo || "Sin fecha válida"}</td>
+                        </tr>
+                      ))}
+                    </tbody>
+                  </table>
+                  {errors.length > 100 && (
+                    <small className="text-muted">Mostrando 100 de {errors.length}.</small>
+                  )}
+                </div>
+              </details>
+            )}
             <small className="text-muted d-block mt-2">
               Fuente: <code>GET /api/Boletas/payments?mes=&amp;year=</code> (SAM.API).
             </small>