diff --git a/88.md b/88.md
index 236b786e..28bed06d 100644
--- a/88.md
+++ b/88.md
@@ -75,5 +75,13 @@ Clients supporting this NIP can check for zaps e-tagging the `kind:7001` event t
 
 The same `kind:7001` is re-zapped on a regular basis per the cadence specified in the event.
 
+## Verifying Payment
+The following conditions must be met to verify a payment:
+
+* Time between zap receipts should be equal or less than the cadence specified in the `kind:7001` event.
+* Amount of the zap receipt should be equal or greater than the amount specified in the `kind:7001` event. For currencies not directly supported by the zap spec, clients should do a best effort conversion to the currency specified in the `kind:7001` event at the time of zap receipt.
+* Zap-receipts should include a zap request `e`-tagging the `kind:7001` event. Zap-receipts might not include a signature (for NWC-automated payments where the subscriber is not present to sign the zap request).
+* Validations specified in [NIP-57](https://github.com/nostr-protocol/nips/blob/master/57.md).
+
 ## Stopping a subscription
 A user who wants to stop a subscription by publishing a `kind:5` deletion request of the `kind:7001` event.