> For the complete documentation index, see [llms.txt](https://help.tpwallet.io/en/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.tpwallet.io/en/wallet-faq-en/btc-wallet/does-a-bitcoin-address-have-to-start-with-a-number.md).

# Does a bitcoin address have to start with a number?

No, there are 1, 3 and bc1, which represent the following:

The address at the beginning of 1 is P2PKH(pay-to-public-key-hash) address, which is the original address, and is called ordinary BTC address; 

The address at the beginning of 3 is P2SH(pay-to-script-hash) address, and the internal address also needs to be segwit, that is, the segwit address. 

The address at the beginning of bc1 is a BECH32 encoded address, an address format developed specifically for segwit, and an segwit address. 

The address at the beginning of 3 and bc1 are smaller and less expensive than that of 1, which can improve the packaging speed of BTC block.