Your coldcard should have arrived sealed in a very special bag: It has a large Coinkite logo, white digits/text, a blue tab, and a barcode with the number underneath. This number is important and we call it the "bag number". Please make note of this number, the Coinkite factory has recorded this number into the secure area of flash memory inside your Coldcard.
Before opening the bag, please inspect the bag for damage or signs of being previously opened. After you pull apart the top seal, it will show the word "VOID".
The purpose of the bag, and its unique number, is to give you confidence that the Coldcard has come directly from the factory and has not been modified by anyone before you start setup.
If you find anything out of place, please contact firstname.lastname@example.org with photos for reference.
This is merely one of many layers of security. Understand that plastic bags can be "hacked" with sharp knives, a heat press and so on. This is an example of "Defense in Depth".
A serialized tear off tab of the bag is included inside. You should use this tab to double check the width of the bag. You can also use a magnifying glass to check the perforations of the tab match the bag. It is important to observe the bottom of the bag is seamless.
We are no longer using this 'green' bag design.
We are no longer using this 'red' bag design.
Connect a power supply to the Coldcard using the USB-C port at the top. Any Micro USB-C cable you already have can be used or you can purchase a magnetic power-only cable from our store. You can connect the USB to a computer, but at this stage, a wall charger or USB power pack is recommended as the Coldcard only needs power, not data.
The first screen you will see looks like this:
If you look closely at the right edge of the screen, there is a small scroll bar and arrow pointing downwards. Use the 5 and 8 keys to move up and down to see the full message.
The complete terms document can be found here. Press the OK key (checkmark, lower right) to accept the terms and continue.
Before a Bitcoin seed is generated, you must select a primary PIN. This is your main defence against random people using your Coldcard when you are not around. Please pick good PIN codes!
On the Coldcard, the PIN consists of two parts, like these examples:
12-34 1234-5678 872323-39843 12-345678
The first part is called the prefix (1234-) and the second, the suffix (-5678). Each part must have between 2 and 6 digits. The prefix determines the anti-phishing words you will see each time you login.
When you pick your PIN code, you'll see the anti-phishing words associated with the PIN prefix. These words will be unique to each Coldcard. You may want to experiment with a few different PIN prefixes until you find some fun or memorable words. Regardless, you will need to remember those words, as it's important to verify the words before proceeding to the second part of the PIN—every time you login to the Coldcard.
You will be asked to confirm the new PIN and enter it a second time to verify it is correct.
Once your PIN has been established, it's time to setup your bitcoin wallet. You should see a menu like this:
If you already have a BIP-39 seed, or a backup from another Coldcard, or even a XPRV (extended private key), you should choose Import Existing menu item. However, most new users will start with New Wallet.
Choose New Wallet to generate 12-24 words using the BIP-39 word list.
The words are then shown to you. Write down the seed words, in order on the provided card, a piece of paper or on a metal plate. Please be careful at this stage and make sure you're 100% certain that each word is recorded correctly. You may also want to make another copy of the seed at this point too (ie. have an extra backup).
Once you've written the words down, press OK to continue to the quiz. The Coldcard will ask you what each word is in random order. The device does this to verify your backup copy is correct. If at any point you are unsure of a word, you may see them again by pressing OK.
If you complete the quiz successfully, the words are saved and your new Coldcard is ready to be used.
If you want to use a BIP-39 passphrase you can enter it at this point to switch to that wallet. Remember to do this every time you want to access the wallet under that passphrase after powering on the Coldcard.
Once your PIN code and master seed have been established, your Coldcard is ready for operation. You should see a menu like this one:
If the USB-C port is connected to a computer from your Coldcard, the device will make itself available to that computer. (The Coldcard is invisible to the attached computer, if any, until the PIN code is correctly entered.) You can use a desktop wallet, such as Electrum or Sparrow to pair with the Coldcard and send transactions to be signed.
Alternatively, you can use a MicroSD card to bring in transactions and sign them.
Take a look at Sparrow's full step-by-step Coldcard guide here: Sparrow Beginner Coldcard Guide
new-electrum.json, is written to the MicroSD
When you want to spend from this wallet:
We support creating 'skeleton' (xpub) wallet files for these systems:
(new in v3.1.1)
When exporting files for Bitcoin Core or Electrum, you may now press "1" at the confirmation screen, and then enter an arbitrary "account number" on the Coldcard. That account number is put as the last hardened component of the derivation path for the wallet's keys.
In this example, if a segwit-style wallet was made, the full derivation path of the first address (non-change) would be:
615' in the the path. By default, account number is zero.
Keep your Coldcard in a safe location. Every time you remove the device from storage to use it, please consider the following:
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