# Permissionless

> A property of a system where anyone can use it or join without asking permission.

Canonical URL: https://fudfomo.co/glossary/permissionless
Source: What The Block! Dictionary v1.0 (last updated 2026-04-25), browsable at https://wtb.fudfomo.co.

## Definition

A permissionless system lets anyone connect, transact, or build on it without first signing up or being approved. Bitcoin and Ethereum are permissionless: you can run a node, hold a wallet, or deploy a contract without identifying yourself.

Permissionless does not mean lawless. Local rules still apply, especially when funds touch regulated services like exchanges or fiat on-ramps.

## Related terms

- [Trustless](https://fudfomo.co/glossary/trustless): A system where users do not need to trust each other or a central party for it to work as expected.
- [Decentralised](https://fudfomo.co/glossary/decentralised): Spread across many independent participants, with no single point of control.
- [Immutable](https://fudfomo.co/glossary/immutable): Cannot be changed once recorded. The standard property of confirmed blockchain history.
- [Blockchain](https://fudfomo.co/glossary/blockchain): A shared digital record of transactions that no single person or company controls. Everyone can read it, and changes are extremely hard to fake.

## See the full catalogue

What The Block! covers more than 2,000 plain-English crypto terms, delivered as embeddable hover-state tooltips for crypto exchanges. https://wtb.fudfomo.co