Crypto & payments
The 15-minute price lock: how it actually works
Why the amount you owe is fixed for 15 minutes from when you start checkout, what happens if the chain takes longer than that, and the (small) risk you carry as a buyer.
Satmart Team · April 25, 2026 · 2 min read
When you start checkout we generate a single-use deposit address and quote the exact amount you owe in your chosen coin, computed at that moment's spot rate. From that point you have 15 minutes to send the payment — the quoted amount is locked, even if the spot rate moves.
Why 15 minutes
Long enough to send a transaction from any reasonable wallet (Ledger, MetaMask, exchange withdrawal). Short enough that the spot rate is unlikely to drift meaningfully against either side.
15 minutes is also roughly the time within which the cheaper networks (Tron, BTC at average fee, ETH at average fee) reliably confirm.
If the chain takes longer
If your transaction broadcasts inside the 15-minute window but the network only confirms after it has expired, we still honour the locked price if the spot rate has moved less than 2% in the interval. Above 2%, we either credit the under/overpayment to Store Credit or refund — see clause 5.2 of the Terms of Service.
If your transaction does not broadcast at all in the window (the most common cause is a wallet still loading or a hardware key needing reconnection), the address remains valid but the price is requoted at the next-block spot.
What this means for you
In practice, almost every payment lands well inside the window and the lock is invisible. The reason we promise it explicitly is so you can be confident that the price you saw is the price you pay — without that promise, a small spot move during checkout would feel like a bait-and-switch.
The exception is volatile-market days: when the market is moving fast in either direction, send promptly. The lock will still apply, but the 15-minute window is your friend — not a buffer to walk away from.