As of December 2021, UK mobile network providers are legally required to sell smartphones unlocked by default, meaning they cannot be sold locked to a specific network. This ban was implemented by the telecoms regulator Ofcom to make it easier for consumers to switch providers and access better deals. Prior to this rule, networks could sell phones locked to their service, often requiring customers to pay a fee (typically around £10) and face potential difficulties to unlock them.

While the ban applies to all new sales, phones purchased before December 2021 may still be locked to a network. Customers can still unlock a phone that is locked, even if it was bought before the ban, by contacting their network provider. Generally, if a customer has finished their contract, the network is not allowed to charge a fee for unlocking. Some networks, like iD Mobile, supply phones unlocked from day one with no charge or time limit. The process of unlocking a phone is legal and can be done directly through the network, often for free, without needing to use third-party services.