BIP 174
Partially Signed Bitcoin Transaction Format
Original title: Partially Signed Bitcoin Transaction Format
- Status
- Deployed
- Type / Layer
- Specification / Applications
- Author
- Ava Chow
- Assigned
- Status verified
- Source
- github.com/bitcoin/bips/blob/master/bip-0174.mediawiki
Summary
Defines a binary format (PSBT) for partially signed transactions that can be passed between multiple signers. Before it, the way an unsigned or partially signed transaction was represented was implementation-dependent, which made it hard for people using different wallet software to collaborate on one transaction. PSBT solves this by carrying everything a signer needs in a single structure. The BIP states two goals: to create an extensible standard usable across clients, and to let signers operate offline. Signing normally requires access to the UTXOs being spent; because PSBT carries that information along, air-gapped and hardware wallets can sign without direct access to the UTXO set — and without the risk of being defrauded about input amounts and thus about the fee. The format is key-value based so new fields can be added without breaking existing parsers.
Why it matters
It became the de facto interchange language for multisig and collaborative custody. It underpins the hardware-wallet workflow of signing without ever exposing private keys, and is implemented by Bitcoin Core and the major hardware wallets.
Related BIPs
Related articles
This page carries a summary, not a translation. The original document is authoritative, and the metadata above — including Status — was transcribed from the bips repository on the verification date shown. Always consult the original when implementing or verifying.