SIM Only Mobile Phone Contracts | Could one work for me?

A SIM-only mobile contract is exactly what it sounds like: a mobile phone plan that provides you with a SIM profile and a monthly allowance of minutes, texts, and data—but doesn't include a handset.

In other words, you are only paying for the network connection, avoiding the hefty premium of paying off a brand-new device. SIM-only plans work perfectly for people who already own a phone they are happy with, or who prefer to buy their handsets outright to save money in the long run.

How SIM Only Works in 2026

If you are coming off a traditional phone contract, moving to a SIM-only plan is incredibly straightforward. Here is what you need to know:

The SIM (Physical or eSIM): Depending on your phone, your new provider will either post you a traditional physical SIM card (a small microchip) or send you an "eSIM" profile. With an eSIM, there is no waiting for the postman—you simply scan a QR code or download the provider's app to activate your new network instantly.

Keeping Your Phone Number: Switching networks doesn't mean losing your number. To bring your current number to your new SIM-only plan, simply text the word PAC to 65075 from your old SIM. You will receive a code within seconds. Give this PAC code to your new provider, and they will port your number over (usually within one working day).

Choosing Your Plan: You will select a monthly tariff based on your data needs. These range from cheap 1GB plans to unlimited data powerhouses. Top tip: Pay close attention to promotional pricing. Some deals advertise a deeply discounted rate (e.g., £3/month) for the first three to six months before reverting to a higher standard price.

Flexibility & Freedom: Because you aren't paying off a £1,000 smartphone, SIM-only contracts offer massive flexibility. Many are available on 1-month rolling contracts. This means you aren't tied into a 24-month commitment and can leave or switch providers with just 30 days' notice if you find a better deal elsewhere.

Compatibility: Because Ofcom banned UK mobile networks from selling "locked" phones back in December 2021, almost any modern smartphone is automatically unlocked and ready for a SIM-only plan. Unless your phone is older than 2021, you won't need to worry about network compatibility issues.

Ultimately, SIM-only plans are the most cost-effective way to run a mobile phone. If you can resist the urge to upgrade your handset every two years, switching to a rolling SIM deal will save you hundreds of pounds annually.

Best SIM Only Deals

The best deals are changing constantly, and what's best for one person might not be best for the next person. Why? People have different data needs, budgets, and levels of commitment. That said, here are some of the more popular deals at Uswitch at the time of writing:

Best the best, current deals for you by clicking below. You can then search for the bestselling deals, the cheapest costs, the most data, and other factors.