diff --git a/04-onion-routing.md b/04-onion-routing.md
index 63fbdf34f..e550f97d6 100644
--- a/04-onion-routing.md
+++ b/04-onion-routing.md
@@ -395,7 +395,8 @@ The final node:
       all HTLCs in the set.
     - if the total `amt_to_forward` of this HTLC set is equal to or greater
       than `total_msat`:
-      - SHOULD fulfill all HTLCs in the HTLC set
+      - SHOULD fulfill the minimal subset of those HTLCs in the HTLC set which are required for payment
+      - SHOULD reject other "unnecessary" HTLCs in the HTLC set.
     - otherwise, if the total `amt_to_forward` of this HTLC set is less than
       `total_msat`:
       - MUST NOT fulfill any HTLCs in the HTLC set
@@ -436,6 +437,13 @@ otherwise meets the amount criterion (eg. some other failure, or
 invoice timeout), however if it were to fulfill only some of them,
 intermediary nodes could simply claim the remaining ones.
 
+There are cases where the sender attempts payments for the same invoice from multiple wallets
+(usually because one part of the first payment is stuck).  For example, a wallet could send
+50% of the payment in one part which arrives at the destination, and another 50% which does
+not.  The sender tries another wallet, which pays 100% of the payment.  In this case, the 50%
+HTLC should be rejected, as the 100% is sufficient.  This can be determined by ordering the
+HTLCs in the set in descending amount order, and iterating until the amount requirement is fulfilled.
+
 ## Route Blinding
 
 1. subtype: `blinded_path`
@@ -1518,7 +1526,7 @@ An _intermediate hop_ MUST NOT, but the _final node_:
   - if the payment hash is unknown:
     - MUST fail the HTLC.
     - MUST return an `incorrect_or_unknown_payment_details` error.
-  - if the amount paid is more than twice the amount expected:
+  - if the amount paid exceeds the expected about by more than 5000msat or 1% (whatever is greater):
     - SHOULD fail the HTLC.
     - SHOULD return an `incorrect_or_unknown_payment_details` error.
       - Note: this allows the origin node to reduce information leakage by