bc1q

bc1q is a prefix used for Bitcoin addresses that utilize the Bech32 encoding scheme. Bech32 is a data encoding system designed for Bitcoin transactions, aiming to improve usability and reduce errors. Addresses starting with bc1q are known as native SegWit addresses, or bech32 addresses. This format offers several advantages over older Bitcoin address formats, such as improved checksums to detect typos and case-insensitivity, making them easier to read and input.

The SegWit, or Segregated Witness, upgrade to the Bitcoin protocol introduced a new address format to support its functionalities. Native SegWit addresses, identified by the bc1q prefix, are designed to be more efficient in terms of transaction fees, as they require less data to be processed by the Bitcoin network. This efficiency is a direct result of the SegWit upgrade, which separates signature data from transaction data.

When a Bitcoin address begins with bc1q, it signals that the address is compatible with SegWit and uses the Bech32 encoding. This means that transactions sent to or from such addresses can benefit from the lower transaction fees and other optimizations associated with SegWit. While older wallets and services might not fully support bc1q addresses, most modern Bitcoin software and exchanges do. The adoption of bc1q addresses represents a step towards a more efficient and user-friendly Bitcoin ecosystem.