4 Bitcoin Address Types in 2026: Which One to Paste in a Swap (and the Bitcoin Cash Look-Alike Trap)

By Swappr Editorial (GSPTeck) · Published 2026-10-17 · Last verified 2026-10-17

When you swap into Bitcoin, the swap form asks for one thing that cannot be undone: your BTC receiving address. Bitcoin has four address formats in common use, and they start with 1, 3, bc1q or bc1p. All four are valid, but they differ in fees, support and how easily they can be confused with something else, especially with Bitcoin Cash, which shares Bitcoin’s oldest format. This guide explains each prefix, which one to paste, and five checks that catch the BTC/BCH mix-up before you send. Educational only; swaps in Swappr are processed by FixedFloat.

Swappr in one line: a free Android app by GSPTeck for multi-coin swaps: pick the coin you have and the coin you want, check the estimate and min/max limits, choose Fixed or Float rate, paste your receiving address and send the deposit from your own wallet. Features that matter here:

• Both Bitcoin and Bitcoin Cash are in the coin list, and every pair shows its own minimum and maximum.
• The address field carries the in-app reminder “Always double check!”.
• No account and no recovery phrase: you receive to an address you choose.

Honest comparison: withdrawing BTC from an exchange also asks you for an address, but the exchange may restrict which formats it sends to; a DEX on another chain gives you wrapped BTC rather than native bitcoin. An instant swap like Swappr delivers native BTC to whatever address you paste, which makes the format choice yours. The Swappr app page with the Google Play download has the full flow.

The four Bitcoin address formats at a glance

According to BIP-173, bech32 addresses use the human-readable part bc for mainnet, never mix upper and lower case, and leave out the characters 1, b, i and o after the separator to reduce misreading. A native SegWit key-hash address is 42 characters long; a script-hash one is 62. BIP-350 introduced bech32m for witness version 1 and later, which is why Taproot addresses start with bc1p.

Which one should you paste?

For receiving BTC from a swap, use a bc1q address from your wallet unless you have a reason not to. Blockstream’s help center on Bitcoin transaction types describes native SegWit as having the widest compatibility across exchanges and services, with Taproot offering slightly lower fees on some spends and better privacy, and recommends falling back to bc1q when a service does not accept bc1p. For a full walkthrough of one common route, see how to swap USDT on TRC20 to Bitcoin on Android in five steps.

• bc1q: the safe default. Widely accepted and cheaper to spend later than the older formats.
• bc1p: fine if your wallet supports it and the swap form accepts it. If the form rejects it, use bc1q from the same wallet rather than forcing it.
• 3…: works, but spending from it later typically costs more than from a bc1q address. Use it if it is what your wallet or multisig setup gives you.
• 1…: works on Bitcoin, costs the most to spend later, and is the format that looks identical to a Bitcoin Cash legacy address. Avoid it for new receiving addresses where you can.

Any format can receive from any other at the protocol level; the difference is cost and support, not whether the coins arrive.

The Bitcoin Cash look-alike trap

Bitcoin Cash split from Bitcoin in August 2017 and kept Bitcoin’s address formats, so for a while a BCH address and a BTC address looked exactly alike: both started with 1 or 3. Bitcoin Cash later adopted the CashAddr format to end that confusion. The CashAddr reference describes it as a Base32 format that “prevents confusion” with the legacy encoding also used by Bitcoin, with the prefix bitcoincash: and payloads starting with q (P2PKH) or p (P2SH). The same reference notes that wallets may hide the prefix, so a BCH address can appear as just qq… or qp….

Where this bites in a swap:

• Pasting a BCH legacy address into a BTC field. A 1… address from a Bitcoin Cash wallet is also a valid Bitcoin address, so the form can accept it. The BTC arrives at an address on the Bitcoin chain that your Bitcoin Cash wallet will not show. Whether you can ever reach those coins depends on whether you can import that key into a Bitcoin wallet; do not count on it.
• Pasting a BTC address into a BCH field. The mirror image. Some services reject a 1… address for BCH, others accept it; either way, receive BCH to a CashAddr address from a BCH wallet.
• Confusing bc1q… with q…. Both contain a q near the start. A BTC bech32 address always begins with bc1; a CashAddr address begins with bitcoincash: or directly with q or p.

FixedFloat’s FAQ on address validation explains that an address is rejected when its network does not match the selected currency. That catches many typos, but it cannot catch an address that is genuinely valid on both chains, which is exactly the legacy-format case.

Five checks before you send the deposit

1. Copy from the right wallet screen. Open the Receive screen for Bitcoin when swapping into BTC, or for Bitcoin Cash when swapping into BCH. Never reuse an address from history; our guide to copy-pasting crypto addresses safely before a swap explains why.
2. Read the prefix. For BTC expect bc1q or bc1p (or 3/1 if your wallet only offers those). For BCH expect bitcoincash:q, bitcoincash:p, or a bare q/p.
3. Check the length and case. A bc1q key-hash address is 42 characters, all lower case or all upper case. Mixed case in a bech32 address is a sign something was edited.
4. Confirm the coin in Swappr matches the wallet. “Bitcoin” and “Bitcoin Cash” sit close together in many coin lists. Re-read the pair before tapping Swap now.
5. Fill the refund address on the deposit coin’s network. If the form asks for one, it belongs to the coin you are sending, not the coin you receive; our refund address vs receiving address guide covers the difference.

After you send: confirm on the right explorer

Save your deposit transaction ID, then look up the payout on a Bitcoin explorer for BTC or a Bitcoin Cash explorer for BCH. Searching a BCH address on a BTC explorer (or the reverse) shows nothing and causes needless panic. The steps to follow an order from deposit to payout are in our guide to tracking a crypto swap with its transaction ID.

A note on Lightning: a Lightning invoice usually starts with lnbc and is not an on-chain address. Paste one only where the coin selected is explicitly Lightning BTC; a regular BTC field needs an on-chain address.

FAQ

Is bc1q or bc1p better for receiving a swap?

bc1q is the most widely accepted. bc1p works where supported and can be slightly cheaper for some later spends. If the form rejects bc1p, use bc1q.

Can I send BTC to an address that starts with 3?

Yes. It is a valid Bitcoin script-hash address. It just tends to cost more to spend from later than bc1q.

Why does my Bitcoin Cash address start with q?

That is CashAddr with the bitcoincash: prefix hidden. It is the format to use for receiving BCH.

Can a swap service tell a BCH legacy address from a BTC one?

Not by format alone. A legacy 1… address is valid on both chains, so only your own check catches the mix-up.

Sources

• BIP-173: bech32 address format (checked 2026-10-17)
• BIP-350: bech32m for witness v1+ (checked 2026-10-17)
• BIP-13: address format for P2SH (checked 2026-10-17)
• Bitcoin Cash protocol reference: CashAddr encoding (checked 2026-10-17)
• Blockstream Help Center: transaction types (checked 2026-10-17)
• FixedFloat FAQ and Swappr on Google Play (checked 2026-10-17)