A payment with
clear terms.

Postbox holds an addressed BNB payment until the recipient collects it or its deadline passes.

The payment

The sender records a receiving wallet, a principal amount and an expiry timestamp, depositing the principal plus a reserved service fee. The receiving wallet can collect strictly before that timestamp. From the expiry timestamp onward, collection is blocked and the sender can recover the entire unclaimed deposit, including its reserved fee.

The sender cannot cancel early. The recipient cannot change the amount or deadline. A payment link is public navigation, not a bearer key. Knowing a link or payment number does not let another wallet collect its funds.

The contract accepts deadlines between 60 seconds and 365 days from creation. The interface offers one hour, one day, seven days and thirty days. Displayed dates use the visitor’s local time; the onchain block timestamp decides eligibility.

Fees

The fixed service fee is 0.5% of the principal, rounded down to whole wei. It is reserved on creation and becomes payable to the immutable treasury only after successful collection. An unclaimed payment recovered after expiry returns both principal and reserved fee. Blockchain gas is separate and is not refunded.

Example: a 0.01 BNB payment reserves a 0.00005 BNB fee, for a 0.01005 BNB deposit before gas. Successful collection sends exactly 0.01 BNB to the recipient. Expired recovery sends the sender the full 0.01005 BNB deposit before recovery gas.

Who can move funds

Only the named recipient can call collection. Only the original sender can call recovery after expiry. Each may select another destination address for their own authorized withdrawal, which helps if their wallet cannot receive BNB. The app defaults to the connected wallet and shows the destination before signing.

The treasury can withdraw accrued fees only. It cannot take waiting deposits, change a recipient, move a deadline, pause exits, replace code or change the fee. There is no administrator upgrade function. Unsolicited or forcibly sent BNB does not create a payment and has no rescue function.

Network and contract

Reading public deployment details...

Reading the active network... Local tests and public testnet transactions are engineering checks, not an independent security audit.

Limitations

This is unaudited software. Contract bugs, compromised wallets, malicious websites and network outages can affect funds. Verify the receiving address and network yourself. A wrong receiving address cannot be edited after funding. Before expiry neither the sender nor the project can reverse the payment.

The recipient needs gas to collect; this is not a gas-sponsored transfer. Links contain a network and payment number, not a secret. Sender, recipient, amount and deadline are public onchain. The interface loads up to 500 sent and 500 received payment records; another payment can be opened directly by its number.