Our crypto checkout credits a payment the moment it lands on the blockchain, with no operator in the loop. The flip side is a single hard requirement: the sum that arrives must equal the sum on the invoice, down to the last decimal digit. Here is what that rule protects, why exchanges keep breaking it, and the one habit that avoids the problem entirely.

The amount is the only thing that identifies you

A bank transfer carries a reference line. A blockchain transfer carries nothing of the kind: no invoice number, no customer name, no comment we could rely on. Dozens of customers send coins to the same receiving address every day. The single property that tells one incoming transfer from another is how much was sent.

So each invoice is issued with its own unique value: the price converted into the chosen coin plus a short, unique sequence in the fractional part. 20.2266 USDT instead of 20.23, 14.2621 SOL instead of 14.26. When a transfer appears on the address, the system looks for an open invoice with exactly that figure. Those last digits do the job an invoice number does elsewhere.

If a different sum arrives — smaller or larger, even by a single digit — there is no invoice with that figure, the transfer cannot be assigned to anybody, and nothing is credited. Such coins sit on the address with no owner we can prove. We treat that transfer as lost; it is not refundable, and the SERVA ONE Refund Policy says so explicitly.

Where the "wrong amount" usually comes from

  • The exchange takes its fee out of the sum you typed. You enter 20.2266, the platform withholds its withdrawal fee, and 19.2266 shows up on-chain. Only a few exchanges let you add the fee on top.
  • Decimals get cut. Many withdrawal forms accept two or four decimal places and silently round the rest away.
  • Step limits. A form may quietly snap the amount to the nearest allowed increment.
  • Wrong network. USDT or USDC pushed over ERC-20 or BEP-20 will never reach a TRC-20 address; a TON transfer with a mangled address is gone too.
  • One transfer for two invoices, or two transfers for one. Neither can be matched, because no single transfer equals a single invoice.

Every item on that list ends the same way: the figure on the blockchain is not the figure on your invoice.

The habit that solves it: never pay straight from an exchange

If the service you are sending from cannot transmit an exact figure with every decimal, do not use it as the final hop. Move the coins to a wallet whose keys belong to you, and make the payment from there. A self-custody wallet accepts any number of decimals and shows the network fee as a separate line, so the amount you type is the amount that arrives.

A good option is SafePal: a free app for iOS and Android with an offline (cold) mode that covers TRON (USDT TRC-20, TRX), Bitcoin, Litecoin, TON, Dogecoin and Solana. Trust Wallet, Tonkeeper (for TON) or any comparable non-custodial wallet will do the same job.

  1. Withdraw slightly more than the invoice from the exchange to your own wallet, leaving room for the network fee of the second transfer.
  2. On the payment page choose the coin, then copy the amount with the Copy button instead of retyping it.
  3. In your wallet paste the address and the copied figure. Double-check the network: USDT and USDC travel over TRC-20 only.
  4. Confirm that the fee is charged in addition to the amount, not subtracted from it, then send.
  5. Leave the payment page open. It polls the blockchain every few seconds and marks the invoice paid on its own; the countdown on the page shows how long the invoice stays valid.

Thirty-second check before sending

  • Amount copied from the payment page, every decimal intact.
  • Fee paid on top; the wallet preview shows exactly the invoice figure arriving.
  • Network identical to the one named on the payment page.
  • One transfer, one invoice.
  • Sent while the invoice timer is still running.

Already sent the wrong sum?

Open a ticket for the Financial department with the transaction hash (TXID), the coin, the sum you sent and the invoice figure. Such cases are reviewed by a person, which takes time, and crediting cannot be promised: by our rules an unmatched transfer counts as lost.

This is not red tape. On a public blockchain with a shared receiving address, the exact amount is the only reliable identifier of a payment — the same mechanism every automatic crypto checkout relies on. Sticking to it is what lets us credit your balance in minutes without a payment processor.