Bitcoin address formats, and why yours starts the way it does

Bitcoin addresses come in several formats. They all work, but they are not identical in cost.

Starting with 1

The original format. Still valid everywhere, the most expensive to spend from.

Starting with 3

Script addresses, commonly wrapped SegWit. Cheaper than the originals and very widely supported.

Starting with bc1q

Native SegWit. Cheaper again, and what most wallets now give you by default.

Starting with bc1p

Taproot. Newest, with some privacy and efficiency benefits. Support is good but not universal, so check the sending side accepts it.

What to do with this

If your wallet offers native SegWit, use it: you pay less in fees for the same transaction. If a service refuses an address, it is usually an older system that has not added support for the newer format, and most wallets can produce an older style address on request.

Swap Heaven accepts the standard formats and checks the shape before you send.