Bitcoin message signing is built into the BitBoxApp for both new and previously used addresses. You do not need to install Electrum to sign a message with your BitBox. Follow How to sign a Bitcoin message in the BitBoxApp to use this built-in feature.
If you prefer to use Electrum, follow this guide to sign the requesting service's message with the correct address, verify the signature, and submit it in the required field or format. Signing a message does not send bitcoin or incur a network fee, and your private keys remain on the BitBox.
A valid signature proves control of the selected address. It does not prove your identity, legal ownership of funds, or control of other addresses. The requesting service decides which address types and signing formats it accepts.
Before you begin
This procedure supports Bitcoin mainnet addresses in a single-signature wallet using Native SegWit (bc1q) or wrapped SegWit (3). It does not support Taproot (bc1p), legacy (1), multisignature wallets, or test networks. An address prefix alone does not establish compatibility: the address must belong to the supported account connected to your BitBox.
- Use Electrum on your computer, downloaded from the official Electrum website.
- Your BitBox must already be set up, with its firmware updated through the BitBoxApp. Close the BitBoxApp completely before using Electrum so it does not occupy the device connection.
- Have the exact address and complete message supplied by the requesting service ready, and check its submission requirements. Create your own message only if the service explicitly asks you to.
- Open the Electrum wallet connected to the BitBox account containing that address. Each wallet represents its selected account and address type; it does not automatically include every account in the BitBoxApp. If you have not connected it yet, follow How to connect your BitBox with Electrum. A watch-only wallet can display addresses but cannot sign through your BitBox.
Check what you are being asked to sign
Sign only a message you understand and expected to receive from the intended service. If the request is unclear or asks for recovery words, private keys, passwords, an optional passphrase, or a wallet backup, stop. None of these secrets is needed to prove address control.
Sign and verify the message
In the Electrum wallet for the correct account, select the requested address and sign the complete message. The screenshots are separate examples: use the address and message from your own request throughout.
- In Electrum, open the Addresses tab. If it is hidden, select View → Addresses from the menu bar. The tab lists addresses in the selected wallet.
- Find the exact requested address, checking receiving and change addresses as needed. Right-click that address and select Sign/verify message. The signing window opens with the address filled in. If you cannot find it, use the troubleshooting guidance below rather than choosing a different address.
- Check the complete Address field against the service's request, then paste the supplied message into the Message field. Preserve its capitalization, punctuation, spaces, and line breaks.
- Select Sign. Connect and unlock your BitBox if prompted; the device asks you to review the signing request.
- On the BitBox display, review the complete address and message. Confirm on the device only if both match the original request exactly. Reject the request if either differs or you do not understand it. After confirmation, Electrum fills the Signature field.
- Select Verify in the same window. Electrum displays Signature verified when the signature is valid for the address and message in the window. If verification fails, resolve it before submitting the result.
Share the signed result
Return to the requesting service's verification form or designated channel. Share the proof only with the intended recipient because it can associate you with that Bitcoin address.
- In Electrum's signing window, select and copy the complete value in the Signature field.
- If the service provides a signature field, paste only the signature into it. Do not add the Bitcoin address or original message to that field. If the service also requests the address or message, provide them unchanged in their separate fields or in the exact format it specifies.
- Submit the result using the service's instructions and complete any additional confirmation or authentication it requests.
The message is signed and locally verified when Electrum displays Signature verified for the correct address and message. The service must separately confirm that it accepts your proof; copying or submitting the signature alone does not establish acceptance.
If something does not work
The requested address is not listed
Check that you opened the Electrum wallet connected to the correct BitBox account and address type, including the intended optional-passphrase wallet if you use one. Look through both receiving and change addresses. If filters are visible above the address list, select All types and All status so they do not hide addresses by type or usage.
If you need to connect another account, use the account-selection guidance in the connection guide linked above. Do not substitute another address when the service requires a specific one.
Signing is unavailable or the address type is unsupported
If Sign/verify message is missing from the address menu, check whether you opened a watch-only or multisignature wallet. Use the wallet connected directly to your BitBox for the supported single-signature account. Do not import recovery words or private keys into Electrum to enable signing.
If Electrum reports that the address type is unsupported, ask the requesting service which compatible address and signing format it accepts before trying another method.
Electrum does not detect the BitBox
Close the BitBoxApp and any other application using the device, reconnect and unlock your BitBox, and try again. If detection still fails, follow the connection guide linked above. For an unresolved connection error, contact BitBox Support with your Electrum and firmware versions, operating system, and non-sensitive error text. Do not send wallet secrets or a wallet backup.
Verification fails in Electrum
If Electrum displays Wrong signature, check that the address, message, and signature have not changed. Compare the message with the original request, including spaces and line breaks. If you correct the message or address, sign it again and verify the new signature.
The service rejects a verified signature
If Electrum displays Signature verified but the service rejects your submission, check that you copied the complete signature unchanged and entered only that value in its signature field. If the service separately requested the address or message, check that those values match the ones verified in Electrum, including all message spaces and line breaks.
If the submission matches the service's requirements, ask the service whether it accepts the address type and Electrum's signing format. A valid signature does not guarantee that the service accepts it.