How to Customize a Transaction Nonce

A nonce is the counter attached to every transaction you send from an address: your first is 0, your second is 1, and so on with no gaps. The network processes them strictly in that order. Customizing a transaction nonce means typing that number yourself instead of letting the wallet fill it in - which is how you replace a stuck payment, because a replacement is simply a second transaction claiming a number already in use.

Where the setting lives

In the MetaMask extension it is under Settings, then Advanced: a toggle called "Customize transaction nonce". Turn it on and a small nonce field appears on every confirmation screen from then on. Rabby and Frame expose the field by default. If you sign with a Ledger or Trezor through MetaMask, nothing changes - the hardware wallet signs whatever nonce the interface hands it.

Which number to type

Almost always: the nonce of the transaction you are trying to replace. Find it in the wallet's transaction details or on a block explorer, type that exact number, and pay a higher fee than the original did. Leave the field alone for ordinary payments. The wallet's own count is right nearly all of the time, and overriding it out of habit is how people create problems they did not have.

The two mistakes to avoid

The first is typing a number already used by a confirmed transaction - the network rejects it with a "nonce too low" error, because that seat is taken forever. The second is leaving a gap: type 45 when your last confirmed was 43, and nothing happens at all. Your transaction waits, invisibly, until something fills number 44. Counts are also per network, so your Ethereum mainnet nonce and your Arbitrum nonce are separate numbers that happen to look alike.

Think of it as a numbered ticket rather than a setting to optimise: useful exactly once, when something is stuck, and best left untouched otherwise. If a payment is sitting pending right now, start here, and overwriting it by hand puts the nonce to work.