© 2026 Della Group. All Rights Reserved.
Okay, so the biggest screw up I see with Coldcard newbies? They skip backing up the seed words properly. Like, they scribble 'em on a napkin or snap a phone pic. Boom. Phone gets hacked, napkin gets lost, and poof-your Bitcoin's gone forever. Happened to a buddy of mine. Don't be that guy.
Instead, do this right from jump. Grab a metal seed plate or at least two sheets of quality paper. Write 'em down twice, store in separate fireproof spots. Test the backup later by wiping the device and restoring. Why does this matter? 'Cause Coldcard's air gapped magic only works if you control the seed. No seed, no sats.
Your Coldcard shows up in a tamper evident bag with a number on it. First thing: check that bag. Torn? Suspicious? Contact Coinkite ASAP. Power it on-hold the power button top left on models like the Q or Cube.
It boots, shows the bag number. Match it exactly or freak out. Scroll through every screen with the arrows. Sometimes it asks you to press a number at the bottom to prove you read it. Miss that? Loops back, you'll think it's busted. In my experience, this anti phishing stuff saves lives.
Now pick "Choose PIN Code." It's got two parts: PIN-1 (like 123456) then two anti phishing words pop up. Memorize those words-they're unique to your device. Enter PIN-2 next. Make 'em long, random. No birthdays. Got it? You're in.
Practice entering it blindfolded later. Muscle memory wins.
Pick New Wallet. It spits out words one by one. Write 'em in order. Then it quizzes you-type back 12 or whatever it asks. Nail it? "Ready to Sign!" screen. That's your home base.
But wait-passphrase option? Game changer. Adds a secret word (up to 100 chars) for "plausible deniability." Like hidden wallets on the same seed. I usually set one: go to Passphrase menu, enter it, hit Apply. Save to MicroSD if you're careful- but that card's now hot property. Lose it? Retype next time.
What's next? Pair it with software. Sparrow Wallet's my go to. Free, open source, Bitcoin only. Download from sparrowwallet.com.
Connect Coldcard via USB. Enter PIN. In Sparrow: File > New/Restore > Hardware Wallet > Coldcard. It scans, grabs your xPub (watch only data). Boom, wallet shows up.
Air gapped purists? Export xPub to MicroSD or QR. Sparrow imports it. No cable ever touches your signer after setup. Safer, but fiddly first time.
| Method | Pros | Cons |
|---|---|---|
| USB | Fast setup | Theory risk if PC compromised |
| SD/Air Gapped | Max security | Slower, card handling |
I started with USB, switched to SD. You'll figure your style.
In Sparrow, Addresses tab. Right click a fresh one (starts with bc1q for SegWit-lower fees). Copy. Send from exchange. Watch it hit in Transactions tab.
Pro move: First receive? Tiny amount, like 50k sats. Prove it works. Check address label-don't send to wrong derivation path. Sound familiar? Exchanges love screwing that up.
Addresses reuse? Nah. Generate new each time. Coldcard has billions. Fees around 1-5 sats/vB now, but SegWit keeps it cheap.
Got sats? Send tab. Paste destination, amount. Max button sends all minus fee. Create Transaction. Sparrow shows inputs/outputs-verify everything. No trust.
Save PSBT to MicroSD. Pop into Coldcard: Ready to Sign > pick file. It displays tx details. Scroll outputs: address, amount match? Good. Sign. Saves signed PSBT.
Back to Sparrow: Load signed file. Broadcast. Watch mempool. Confirmed? Party.
Single sig good. Multisig better. Like 2-of-3: Coldcard + another + software. Sparrow shines here.
Setup: Create wallet in Sparrow, add Coldcard, then another (Tapsigner? iPhone app?). Set 2-of-2 or whatever. Export PSBT needs all keys to sign.
In my experience, start simple. But multisig's why Coldcard rules-signs anything.
Seed gives one wallet. Passphrase? Infinite hidden ones. Enter at boot: Advanced > Passphrase > Edit > type > Apply.
Forget it? Poof, that wallet vanishes. Decoy wallet for thieves? Genius. But test recovery: wipe device, restore seed + passphrase. I lost a test wallet once-lesson learned.
Save passphrase to SD? Risky. I don't. Retype sucks, but secure.
Coldcard nags for updates. SD card method: download .dfu from coldcard.com, copy to SD, insert, Advanced > Upgrade. Air gapped safe.
Why bother? New Taproot support, bug fixes. Latest as of now? Check site. Old firmware? Stuck on legacy features.
Issue: Brick scare? Won't happen if you follow prompts. Backup seed first, obvs.
PIN loop: Wrong entry too many times. Wait or battery drain.
Sparrow no detect: USB off? Settings > Hardware > USB On. Replug.
Tx reject: Check outputs. Fake address? Abort.
SD errors: Format FAT32. Clean contacts.
Honestly, 90% user error. Read screens. Verify twice.
Export xPub for watch only on phone. Electrum too, but Sparrow's king.
QR codes for tx: Coldcard scans PSBT QR from another device. Futuristic.
Dice rolls for seed? Advanced > New Wallet > Dice. Roll 99 times for entropy. Paranoid flex.
Accounts: In Sparrow, add second account same seed. Segregate KYC/non KYC funds. Smart.
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