Quote Expiration

Overview

Quote Expiration limits how long a calculated conversion remains usable. A payment quote connects an invoice amount, Quote Currency, rate, Pay Currency, and expected crypto amount at a specific time.

When the quote expires before the payer sends funds, the application should refresh the rate and create a new expected amount or payment session. Silently retaining the old amount transfers price risk to one party and makes reconciliation ambiguous.

Quote expiration differs from Address Expiration. A quote can expire while an address remains usable under another product, or a temporary white-label address can become invalid even if the customer still sees the earlier price.

It also differs from confirmation timing. A transaction broadcast before quote expiry may confirm later, depending on the product’s payment rule. The policy must state whether timely broadcast, detection, or receipt at the destination preserves the quoted amount.

User interfaces should display a countdown or timestamp and prevent payment instructions from remaining visible after expiry. Logs should preserve the original quote, refresh events, and the rule used when a late transaction is reviewed.

Late-payment rules must specify the event that preserves a quote. Some products use transaction detection before expiry, while others require funds to reach the address or enter a block. The selected rule should reflect network propagation and confirmation delays. Operators need a clear process for transactions broadcast near the deadline but observed only after the quote has expired.

Automated tests should cover the exact boundary second, clock drift, delayed callbacks, and browser tabs left open past expiry. All services should use a consistent trusted time source so the API and interface do not disagree about validity.