No contract.
No commitment.

A no contract SIM deal is a monthly rolling plan with no long-term commitment. You pay month to month and can cancel or switch at any time without an exit fee. Most run on 30-day rolling terms, meaning you give 30 days notice to leave.

Slightly, yes. A 30-day rolling plan typically costs a few pounds more per month than a 12-month contract for the same data. The gap has narrowed considerably though, and in some cases rolling plans now undercut contracted ones. For many people the flexibility is worth any small premium.

Yes. Ask your current provider for a PAC code before you switch. Give it to your new provider when you sign up and your number transfers automatically, usually within one working day. You can keep your number on any SIM plan, including no contract rolling plans.

For unlimited data with no contract, Chattr's Freedom One at £15 per month is the standout: no price rises, no credit check, and strong O2 coverage. For a budget flexible plan, Talkmobile's 15GB at £5.95 per month is the cheapest 30-day rolling SIM we track, with its 80GB plan at £8.95 the best value large allowance.

Most 30-day rolling plans require 30 days notice, so in practice you pay for one final month after you give notice. Some providers let you simply not renew at the end of your current 30-day cycle. Check the specific provider's cancellation terms, but none of them charge exit fees.