diff --git a/47.md b/47.md
index 083dabe2..aa58b5c4 100644
--- a/47.md
+++ b/47.md
@@ -111,6 +111,9 @@ Response:
 }
 ```
 
+Errors:
+- `PAYMENT_FAILED`: The payment failed. This may be due to a timeout, exhausting all routes, insufficient capacity or similar.
+
 ## Example pay invoice flow
 
 0. The user scans the QR code generated by the **wallet service** with their **client** application, they follow a `nostr+walletconnect:` deeplink or configure the connection details manually.