The best SIM-only deals for 2026

Why SIM-only usually wins

If you already have a phone you are happy with, SIM-only is almost always cheaper than a phone-plus-airtime contract. You pay for calls, texts and data only, typically £8 to £15 a month, and you are not still paying for a handset long after it is paid off. Most plans are 30-day or 12-month, so you keep flexibility.

How much data do you actually need?

• Light (up to 5GB): mostly on Wi-Fi, light browsing and messaging.
• Average (10 to 30GB): daily browsing, social media, some streaming on the move.
• Heavy or unlimited: regular streaming, tethering, or you would rather never think about it.

Check your last few bills for your real usage. Paying for unlimited when you use 8GB is money wasted, but constantly buying add-ons is worse.

30-day vs 12-month

A 30-day rolling SIM gives total freedom to leave or switch any month, ideal if you might change phone soon or want to chase deals. A 12-month SIM is often a little cheaper per month for the same allowance, in return for staying put. Pick based on how settled you are.

Network matters as much as price

The cheapest SIM is no bargain if the signal is poor where you live and work. The big networks (EE, O2, Vodafone, Three) run the masts; smaller providers ride on them, often for less. Check coverage at your postcode before committing, and see our 5G coverage guide if fast mobile data matters to you.

Find your deal

Compare on total monthly cost for the data you need on a network with good local coverage. Compare SIM-only deals to see current pricing across networks.

The bottom line

Keep your phone, match the data to your real usage, choose 30-day for flexibility or 12-month for a slightly lower price, and check coverage before signal lets you down. SIM-only is the simplest way to cut a mobile bill.