COLDCARD NFC Push TX

Single-tap broadcast of freshly-signed Bitcoin transactions from a COLDCARD to a phone via NFC technology.

What is NFC Push TX?

NFC Push TX is a revolutionary feature that allows you to broadcast Bitcoin transactions with a simple tap of your phone to your COLDCARD. After signing a transaction, you can tap any NFC-enabled phone to the device and your newly-signed transaction will be immediately broadcasted on the public network.

How It Works

Sign Transaction: Sign your PSBT on the COLDCARD as usual
NFC Tap: Tap your NFC-enabled phone to the COLDCARD
Automatic Broadcast: Transaction is automatically sent to the Bitcoin network
No Manual Steps: Eliminates the need for manual transaction broadcasting

Key Benefits

Convenience: Broadcast transactions with a simple tap
Airgap Maintained: No direct internet connection required on COLDCARD
Multiple Providers: Choose from various service providers or host your own
Privacy Options: Use public services or your own backend for maximum privacy

Supported Devices

This feature is available on COLDCARD Q, Mk5, and Mk4 devices and requires NFC to be enabled. You can configure the service provider in Settings > NFC Push TX.

Privacy Note

For maximum privacy, consider hosting your own Push TX backend. While public services like mempool.space and coldcard.com are trustworthy, using your own service ensures your transaction data stays private.

Try It Now

Test the NFC Push TX functionality with your COLDCARD device.

Go to Push TX

Learn More

For detailed setup instructions and advanced usage, visit our comprehensive documentation.

View Documentation