An address represents a spending condition
An address is a user-facing encoding from which a wallet builds an output script. It is not the private key and it is not an account stored by the network. The same wallet can derive many addresses, and a payment becomes associated with a script output only when a transaction creates it.
Address encodings include a checksum that detects many copying errors. A valid checksum proves internal consistency, not ownership, honesty or the intended network. Malware can substitute a completely valid address controlled by an attacker.
Four common mainnet prefixes
A legacy P2PKH address normally starts with 1. An address starting with 3 is P2SH and may represent nested SegWit, multisig or another script; the prefix alone does not reveal which. Native SegWit version 0 uses Bech32 and generally begins bc1q.
Taproot is SegWit version 1 and uses Bech32m; a mainnet pay-to-Taproot address begins bc1p. BIP 350 replaced Bech32 with Bech32m for witness versions 1 through 16 while retaining Bech32 for version 0. A wallet should perform this distinction automatically.
- 1: usually legacy P2PKH
- 3: P2SH, not necessarily one specific wallet type
- bc1q: native SegWit v0; bc1p: Taproot v1
Compatibility belongs to both ends
The receiver should generate a format its own wallet can later recover and spend. The sender's wallet must recognise and support that format. Older software may not understand newer witness versions even though the address is valid under current rules.
Do not change characters or use a website to 'convert' an address. Changing the output type requires a wallet to derive or supply another valid destination. When restoring a wallet, the seed alone may not make every account visible unless the software also searches the correct derivation path and script type.
Newer does not mean universally cheaper
SegWit changed transaction weight accounting, so spending compatible witness inputs is generally more block-space efficient than spending comparable legacy inputs. The final fee still depends on the number and types of all inputs and outputs and the selected feerate.
Address format is not a privacy grade. Reuse, coin selection, change and information shared with a wallet server can reveal far more than the prefix. Choose a well-supported format deliberately, then verify the entire address on a trusted display before a significant payment.