NowPayments invoice expired — how to retry

When you check out with crypto via NowPayments (our backup gateway alongside SellAuth's native flow), the invoice you see is a price-locked quote. The dollar price is fixed at checkout, the crypto amount is calculated against the spot rate at that moment, and the invoice has a 20-minute expiry window — long enough to send the payment, short enough that the rate doesn't drift while you're paying.

Why invoices expire. Crypto spot prices move continuously. If we let an invoice sit open for an hour, you could check out at a $5 BTC quote, watch BTC drop 10%, and pay $4.50-equivalent — under-fulfilling the order. Or vice versa, you'd overpay. The 20-minute window caps that drift to a tolerable range.

The expired-invoice symptom. You open the NowPayments page, the payment timer counts down to 0:00, and the page replaces the deposit address with "This invoice has expired." If you sent funds after that timer hit zero, the payment may not fulfill automatically.

Step 1: do NOT send funds to an expired invoice. If the timer has already hit zero, the deposit address is no longer monitored for that order. Any payment you send to it lands in our reconciliation queue and takes 24-48 hours to manually credit. Wait until you have a fresh invoice before sending anything.

Step 2: generate a fresh invoice. Close the expired tab. Go back to /products, pick the same tier, and check out again. NowPayments mints a new invoice with a new 20-minute window and a new spot price quote. Send your payment to that deposit address.

Step 3: if you already sent funds to the expired invoice. Email getnimbuscontact@gmail.com with:

• The expired-invoice ID (visible at the top of the NowPayments page).
• The transaction ID (txid) from your wallet showing the payment was sent.
• The expected order tier.

We credit these manually within 24-48 hours. Note that if the spot price moved against you in the gap, the order may auto-credit at a different tier (e.g. a Day pass instead of the Week you intended) — we'll match you to the intended tier at the invoice's original quote, not the current spot price.

Pro tips to avoid expiry.

• Open the invoice when you're ready to pay, not when you're shopping. The clock starts the moment the invoice is generated.
• Use a fast wallet. Wallets that require a hardware-key confirmation, a multisig co-signer, or a custodial-exchange withdrawal flow all eat 5-15 minutes of the 20-minute window. If your wallet flow is slow, generate the invoice last.
• Don't bounce funds through a CEX withdrawal. Coinbase / Kraken / Binance withdrawals process in batches and can take 10-30 minutes to actually broadcast on-chain. If you need to fund from a CEX, withdraw to your wallet first, then start the NowPayments invoice and pay from your wallet.

Why we have two gateways. SellAuth's native flow is the default and handles 95% of crypto checkouts. NowPayments is the fallback for tiers or regions SellAuth doesn't service, and the invoice-expiry rules above apply only to the NowPayments path.