The short answer
Only the holder of an address's private key can produce a valid signature for it. So the proof is: you sign a message (ideally one the other person chose, or one that names them and today's date), and they check that signature against your address. If it checks out, whoever signed controls the address.
This is standard Bitcoin functionality. Most wallets call it Sign message, and the checking side is Verify message.
Why not a screenshot or a test payment?
- Screenshots of a wallet app are trivial to fake and prove nothing.
- A test payment (sometimes called a "Satoshi test": send a tiny, specific amount from the address) does work, but it costs a network fee, waits for confirmation, leaves a permanent trace on the blockchain, and someone has to go and look for it.
- A signed message is instant, free, private until you share it, and checkable by anyone at any time afterwards.
Which addresses can sign
| Address starts with | Type | Can sign a message? |
|---|---|---|
bc1q… (42 characters) | Native SegWit | Yes. Today's default in most wallets. |
bc1p… | Taproot | Yes, with BIP-322 (Xverse, Sparrow, Leather, UniSat) |
3… | Nested SegWit | Yes (if it's a single-key wallet) |
1… | Legacy | Yes. The original format. |
bc1q… (62 characters), multisig 3… | Script / multisig | Not with normal tools: several keys are involved |
One rule matters more than the address type: you must hold the keys. An address on an exchange (Coinbase, Binance, Kraken…) belongs to the exchange, so you can't sign with it. Use a wallet you control.
How to do it
- Pick the address. Usually the one that holds your bitcoin. You don't need any balance to sign, though.
- Sign the message in your wallet. In a browser wallet (Xverse, Leather, UniSat) a website asks and the wallet shows you the message to approve. In a desktop or hardware wallet you paste the message into its Sign message screen. Step-by-step for each wallet: how to sign a message with a Bitcoin wallet.
- Share the address, the exact message and the signature. The other person checks them in any wallet's Verify message screen.
Making the proof easy to check
A raw signature is a block of text, and the person receiving it has to know which tool to use and which format it's in (Bitcoin has two: BIP-137 and BIP-322). That's where people get stuck.
A VerifiedWallet certificate packages the same proof as a link. You sign once on the Get certified page, we check it, counter-sign it with our published key, and give you a certificate page. Anyone who opens it sees both signatures checked in their own browser, and can check them independently without trusting us. Add identity verification if the other side needs to know who you are.
What it does and doesn't prove
- It proves that whoever signed held the private key for that address when they signed.
- It doesn't prove a balance. Anyone can look up an address's balance on a block explorer; the signature tells them the address is yours.
- It doesn't prove who you are, unless identity verification is added (our Tier 2).
- It can't show nobody else has the key. If your recovery phrase has leaked, someone else could sign too. Keep it offline.
Sign once with your wallet: free, no transaction. We counter-sign it and give you a link anyone can verify. From $1.
More guides
How to sign a message with a Bitcoin wallet
Step by step in Xverse, Electrum, Sparrow, Trezor, Ledger and Bitcoin Core.
BIP-322 vs BIP-137: Bitcoin message signing explained
Why there are two formats, which wallets use which, and why Taproot needs BIP-322.
How to prove you own an Ethereum wallet
One signed message, no gas, and it covers every EVM network at once.
How to prove you own a Tron (USDT) wallet
Sign a message in TronLink: no transaction, no TRX burned, works for USDT addresses.
Questions
Does signing a message move my bitcoin or cost a fee?
No. A signed message is not a transaction. Nothing is broadcast, no fee is paid and your coins don't move.
Is it safe to share the signature?
Yes. A signature can't be used to spend from your address, and it only proves you signed that exact message. Never share your recovery phrase or private key, which nobody needs for this.
Can I prove ownership of an address on an exchange?
No. Exchange deposit addresses belong to the exchange and only it holds the keys. Move funds to a wallet you control and certify that address.
Do I need bitcoin in the address?
No. An empty address can sign. Usually you'd certify the address that holds your bitcoin, so the proof is useful to whoever asked.
Can I prove a multisig address?
Not with standard message signing, because several keys control it. VerifiedWallet certifies single-key addresses today.