Mobile phone deals are built to be compared on one number: the monthly price. That figure rarely tells the whole story. Upfront costs, annual increases, the length of the agreement and what happens once it finishes can all change which deal really costs less.
In this guide, V5 Solutions answers the questions people most often ask when choosing a mobile deal, with a simple worked example to show how the sums fit together.
How Do Mobile Phone Contracts Work?
There are two main ways to pay for a phone and its service:
- Handset contract. You get a new phone plus calls, texts and data, usually over 24 or 36 months. Some networks put the phone and the airtime in one agreement, while others split them into a device plan and a separate airtime plan.
- SIM-only. You use a phone you already own and pay only for the service. Terms range from a rolling month to a year or two.
The split matters. With a separate device plan, the handset payments stop once the phone is paid for. With a combined agreement, the monthly price may stay the same after the minimum term, even though the phone has been paid off.
Which Costs Less: SIM-Only or a Handset Contract?
The only fair comparison is the total cost across the same period. Here is an illustrative example using round numbers.
Sam wants a new phone and is offered a 24-month contract at £40 a month with £50 to pay upfront. Over two years, that comes to £1,010 before any annual increases. Alternatively, Sam could buy the same phone unlocked for £600 and take a SIM-only plan at £12 a month, which costs £288 over 24 months. That route totals £888 and leaves Sam free to change plan at any point.
The numbers will be different for you, and sometimes a handset contract does come out ahead, particularly when a network is running a promotion. The point is to work out the totals rather than trusting the monthly figure. If your current phone is in good shape, keeping it and going SIM-only is often the biggest single saving.
Are Refurbished Phones Worth Considering?
For many people, yes. A refurbished phone has been checked and restored by a business, and prices are usually well below new. Look for a clear condition grade, a battery health check and a warranty of at least a year. Your consumer rights are stronger when you buy from a trader than from an individual.
What Happens When Your Mobile Contract Ends?
Networks are required to send you an end-of-contract notice 10 to 40 days before your minimum period finishes. It should show your current price, the price you will pay if you stay and the network's best offers for you. Out-of-contract customers should also hear from their provider each year about the best tariffs available.
Nothing changes automatically when the term ends, which is exactly why so many people overpay. Use the notice as a prompt to review your options before the date passes.
How Can You Negotiate a Lower Price?
Research two or three competing deals first, then contact your provider and say you are thinking of leaving. Ask what they can offer to keep you, and quote the specific prices you have found. If the first offer is not good enough, it is reasonable to ask whether there is anything better.
If you decide to move, you can request your switching code by text. Send PAC to 65075 if you want to take your number with you, or STAC to 75075 if you do not. Your new network uses the code to arrange the transfer, normally within a working day, and your old account closes on the switch date.
Watch Out for Price Rises and Other Costs
Before you sign, check the terms for annual price increases. Under Ofcom rules, contracts taken out since January 2025 must set out any yearly rise in pounds and pence at the point of sale, so you can see the exact cost upfront. Older contracts may still link the rise to inflation, which you can read about in our guide to what rising prices mean for your budget. Over a two or three-year term, this can add noticeably to the total.
Other ways to keep costs down include:
- Asking about social tariffs if you receive benefits such as Universal Credit.
- Checking for discounts when several people in a household use the same network.
- Turning on Wi-Fi calling so you rely less on mobile signal and data.
Your phone renewal date is easy to forget, so it is worth adding it to an annual bills calendar. If paying for your phone has become difficult, MoneyHelper and National Debtline offer free, impartial guidance, and our article on reducing household bills has more ideas.
