Decline code 51 — Insufficient funds
ISO 8583 response code 51.
Code
51 ISO 8583Meaning
Insufficient funds
Type
soft decline
Retry?
Yes, later (e.g. after payday)
What to do
Soft decline. For subscriptions schedule smart retries (e.g. +1, +3, +7 days).
Tell the customer
“Insufficient funds. Please use another card or try later.”