Bitcoin addresses always start with 1, 3, or bc1

A Bitcoin address is a string of letters and numbers that acts like an account number — it tells the Bitcoin network where to send coins. The first character of that address tells you which format the address uses, and that matters because different formats work differently when you send or receive money.

Addresses starting with 1 are the oldest format, called P2PKH (Pay to Public Key Hash). Addresses starting with 3 use a newer format called P2SH (Pay to Script Hash), which often costs less in transaction fees. Addresses starting with bc1 use the newest format, called Bech32, which is the most efficient and usually the cheapest to use.

The letter or number at the start is not random — it is generated by the wallet software based on the format it uses. You cannot change it, and you do not need to. What matters is that when someone sends you Bitcoin, they send it to the address your wallet gives you, and your wallet will recognize and accept it no matter which format it is.

Key Takeaways

  • Bitcoin addresses start with 1, 3, or bc1, and the first character tells you which format the address uses.
  • Addresses starting with 1 are older and work everywhere, but usually cost more in transaction fees than newer formats.
  • Addresses starting with 3 or bc1 are newer formats that typically cost less to use, with bc1 being the most efficient.
  • You cannot choose which format your address uses — your wallet software decides based on the type of wallet you have.
  • All three formats are legitimate and safe; the format only affects transaction cost and speed, not security.

Why addresses start with different characters

The first character of a Bitcoin address is determined by the version byte, a piece of data that your wallet software adds to your public key before converting it into an address. Different wallet types use different version bytes, which is why you see different starting characters.

When your wallet creates an address, it takes your public key (a long string of data that proves you own the Bitcoin), hashes it (runs it through a mathematical function that shortens it), adds a version byte to the front, hashes it again, and then converts the result into the letters and numbers you see. The version byte is what determines whether the address starts with 1, 3, or bc1.

This system exists because Bitcoin has evolved over time. The oldest wallets used version byte 0, which produces addresses starting with 1. Later, developers added version byte 5 for addresses starting with 3. Most recently, they introduced Bech32 encoding, which uses a different system entirely and produces addresses starting with bc1. All three work on the same Bitcoin network — they are just different ways of writing the same information.

What each starting character means for you

If your address starts with 1, you have a P2PKH address. These are the most widely recognized and work with every Bitcoin exchange and wallet in existence. The trade-off is that transactions using these addresses typically cost more in fees because they take up more space in the Bitcoin network's transaction record.

If your address starts with 3, you have a P2SH address. These addresses were designed to support more complex transactions and multi-signature wallets (wallets that require multiple people to approve a transaction). They cost less in fees than addresses starting with 1, but not all older exchanges and wallets recognize them — though this is rare today.

If your address starts with bc1, you have a Bech32 address. This is the newest format and the most efficient. Transactions using these addresses take up the least space in the network's record, so they usually have the lowest fees. However, some older wallets and exchanges still do not support sending to Bech32 addresses, though this is becoming less common.

In practice, this means: if you are receiving Bitcoin from someone, ask them to send to whichever address your wallet gives you. If you are sending Bitcoin to someone, check whether their wallet supports the format you want to use. Most modern wallets support all three formats, so you will rarely run into a problem.

How to find your Bitcoin address

Your wallet software will display your address when you ask it to. In most wallets, there is a button labeled "Receive" or "Get Address" — click it, and the wallet shows you the address to give to someone who wants to send you Bitcoin. The wallet may also display a QR code (a square barcode) that contains the same address in a format that can be scanned with a phone camera.

Your wallet may give you multiple addresses, especially if it is a more advanced wallet. This is normal and intentional — using a different address for each transaction improves your privacy because it makes it harder for someone to link all your Bitcoin transactions together. You can use any of these addresses to receive Bitcoin, and the coins will all go into the same wallet.

Do not worry about which format your address is in. Use whichever address your wallet gives you. If someone tells you they cannot send to your address because of the format, that is a limitation of their wallet, not a problem with your address. Ask them to update their wallet software or use a different wallet.

Why the format matters less than you think

The format of your address affects transaction fees and speed, but it does not affect security. An address starting with 1 is just as find as an address starting with bc1. The security of your Bitcoin depends on keeping your private key secret, not on which format your address uses.

Similarly, the format does not affect whether you can receive Bitcoin. Anyone can send Bitcoin to any valid address, regardless of format. The only time format matters is when you are sending Bitcoin and the recipient's wallet does not support the format you are trying to use — and this is increasingly rare as wallets update.

If you are choosing a new wallet, Bech32 addresses (starting with bc1) are the best choice for new users because they are the most efficient and cost the least. But if your current wallet uses a different format, there is no reason to switch. The differences are small and matter mainly to people who send Bitcoin frequently or in large amounts.

Frequently Asked Questions

Can I change what my Bitcoin address starts with?

No. Your wallet software chooses the format based on the type of wallet you have. If you want a different format, you would need to create a new wallet using different software. However, there is no practical reason to do this — all formats work equally well for receiving Bitcoin.

Is an address starting with 1 less safe than one starting with bc1?

No. The starting character only indicates the format, not the security. All three formats use the same underlying cryptography and are equally safe. Security depends on keeping your private key secret, not on the address format.

What if someone sends Bitcoin to my address and it starts with the wrong character?

This cannot happen. Your wallet only generates addresses in one format, so everyone sending to you will use that format. You cannot accidentally receive Bitcoin at an address in a different format.

Do I need to tell people which format my address is in?

No. Just give them your address or the QR code. They do not need to know or care which format it is. Their wallet will handle the details automatically.

Why do some wallets only support addresses starting with 1?

Older wallets were built before the newer formats existed. Most wallets have been updated to support all three formats, but some very old or rarely-updated software may only recognize addresses starting with 1. If this happens, ask the person to update their wallet software.