What Are Bitcoin Improvement Proposals (BIPs)?

A Bitcoin Improvement Proposal (BIP) is a formal design document that proposes a change to the Bitcoin protocol, describes the technical rationale, and invites public review before the network's users and node operators decide whether to adopt it. BIPs are how Bitcoin evolves without any single company or person controlling the roadmap.

Bitcoin has no CEO, no board, and no headquarters. Yet the software has changed meaningfully since 2009 — new address formats, smarter fee estimation, and privacy improvements have all shipped over the years. The BIP process is the structured way those changes get proposed and vetted, similar in spirit to how the internet's core protocols evolve through open standards documents.

How the BIP process works

The process borrows heavily from Python's PEP system and follows a few consistent stages.

1. Idea and draft — A developer writes up a proposal explaining the problem, the proposed solution, and backward-compatibility considerations.
2. Discussion — The draft is posted to public mailing lists and developer forums where other engineers, node operators, and businesses can critique it.
3. Numbering and formalization — If the idea has enough merit, it's assigned a BIP number and added to the official BIPs repository for the record.
4. Implementation — Someone writes reference code implementing the proposal, often for Bitcoin Core, the most widely run node software.
5. Adoption — This is the real test. Node operators, miners, and wallet developers decide whether to run software that includes the change. Nothing is deployed by decree.

That last step is the crux of the entire system. A BIP can be technically excellent and still go nowhere if the network doesn't adopt it. Conversely, a proposal can't be forced through even by a majority of miners if node operators refuse to enforce it — this is part of how Bitcoin's decentralized governance differs from a typical corporate software release cycle.

Categories of BIPs

BIPs generally fall into three buckets:

Type	Purpose	Example area
Standards Track	Changes affecting consensus, network protocol, or block/transaction validity	Segregated Witness, Taproot
Informational	Design guidelines or general information, not requiring consensus	Best-practice documentation
Process	Changes to procedures around Bitcoin development itself	Proposal process rules

Consensus-changing BIPs are the most consequential because they alter what nodes consider a valid block or transaction. Getting these wrong — or rushing them — risks splitting the network, so they receive the heaviest scrutiny and the longest review timelines, often spanning years.

Soft forks vs hard forks

Most notable BIPs are deployed as soft forks: backward-compatible changes where old nodes still see new blocks as valid, even if they don't understand the new rules. Segregated Witness and Taproot were both soft forks. A hard fork loosens or changes rules in a way that old nodes would reject, requiring every participant to upgrade or risk being left on an incompatible chain. Because hard forks carry a real risk of a permanent chain split, the ecosystem strongly favors the soft-fork path whenever possible.

This ties into a bigger idea covered in our piece on how Bitcoin consensus works: ultimately, node operators — not developers or miners — decide which rules are enforced, because each node validates every block independently.

Why this matters if you just hold or use Bitcoin

You don't need to read the BIP repository to use Bitcoin, but understanding the process explains why upgrades feel slow and conservative compared to typical tech products. That deliberate pace is a feature, not a bug: it protects the predictability that gives Bitcoin its value as a settlement network. It's a similar philosophy to what secures proof-of-work itself — favoring costly, careful change over rapid, centralized iteration.

If you're new to the space, it also helps to understand the difference between protocol-level change management like BIPs and the governance models used in other blockchains and DeFi protocols, where a foundation or token-holder vote can push through changes far faster. For a broader comparison of blockchain designs, see our guide to layer-1 blockchains compared. You can look up unfamiliar terms anytime in the glossary.

Bottom line

BIPs are Bitcoin's open, deliberately slow mechanism for proposing and reviewing protocol changes — no proposal becomes real until node operators and users voluntarily run software that enforces it. That structure trades speed for stability, which is exactly the tradeoff long-term holders and builders on Bitcoin are relying on.