Type your current monthly bill (the headline figure), the network (EE, O2, Vodafone, Three, Sky Mobile, Tesco etc.), the handset model, and how many months remain on the contract.

The tool uses Ofcom market research and operator-published rate cards to estimate your airtime vs handset-finance split — even though most contracts don't show this on the bill.

Pick a usage tier: light (<2GB/month + few calls), medium (5–20GB + 200 mins), heavy (50GB + unlimited calls), or unlimited. The tool matches this to suitable SIM-only plans across MVNOs and full networks.

If you're unsure, check your current bill's data usage page — most users overpay for unused data.

The hero panel shows: monthly saving (current bill vs cheapest matching SIM-only), 24-month total saving, and a months-to-break-even number that includes any exit fee.

If saving is £15+/month and break-even is under 6 months, switching is almost always worthwhile. The result honesty about smaller savings — sometimes loyalty discounts make staying logical.

If you're mid-contract, the Contract Warning shows your projected exit fee, your remaining handset balance, and whether net switching is positive or negative right now.

Often the optimal move is: wait until contract end (free exit), then switch. The tool calculates the exact month from which switching becomes net positive.

The Results tab lists 6–10 matching SIM-only plans ranked by total cost, with monthly price, data allowance, contract length (1-month vs 12-month), 5G availability and notable inclusions (EU roaming, hotspot tethering).

Sweet spot for most users: 1-month rolling contracts at £8–£15. They give flexibility to switch again later as prices fall further.

If you currently rely on the handset bundle, the tool shows refurbished and outright-buy alternatives for your model (or upgrade): typical refurb price, new outright price, and the total ownership cost vs another bundled contract.

Most users find: SIM-only + refurb = save £15–£35/month vs renewing contract; SIM-only + buy new outright (over 36 months) = save £8–£20/month.

UK mobile contracts merged airtime and handset finance to lock customers in. Before 2020, the top tier flagship contract was around £45/month; today's equivalent is £65–£85. Two factors: handset price inflation (iPhone 15 Pro Max RRP £1,199 vs iPhone 11 RRP £729) and CPI+3.9% mid-contract increases compounding.

Ofcom's 2023 ruling on "in-contract price rises" forces transparency — networks must show rises in pounds-and-pence, not just CPI percentages. Pre-ruling contracts can still hide the increase. Read your contract end-date and forecast the actual paid amount through to it before assessing.

The economics favour separating: outright handset (or 0% finance via the manufacturer/Klarna) + SIM-only beats bundled by ~15–25% over 24 months for typical flagship users.

Mobile Virtual Network Operators (MVNOs) lease capacity from one of the four major UK networks. Knowing which network underpins your MVNO matters for coverage:

• EE network: 1pMobile, Plusnet Mobile, Now Mobile, BT Mobile
• O2 network: Giffgaff, Tesco Mobile, Sky Mobile, Lyca
• Vodafone network: Voxi, Asda Mobile, Talk Home, Lebara
• Three network: Smarty, iD Mobile, Honest Mobile

If you've had patchy reception with one major network, an MVNO on a different one may help. Check Ofcom's mobile coverage checker for your home and work postcodes before switching.

5G availability varies — most MVNOs now include 5G but may have lower-priority traffic shaping than the host network's direct customers during congestion.

Pre-Brexit, all UK mobile users had free EU roaming under "roam-like-at-home". Post-Brexit, networks were free to reintroduce charges. Current state (2025/26):

• EE, Vodafone, Three: charge £2/day for EU roaming on most tariffs
• O2: still includes EU roaming free up to 25GB
• Most MVNOs: free EU roaming included (Smarty, Voxi, iD Mobile, Lebara)

If you travel to Europe more than 5 days/year, choosing a SIM-only with included EU roaming saves £10–£14 per trip vs paying daily roaming. Voxi and Smarty are common choices for frequent travellers.

From January 2025, Ofcom requires UK mobile providers to express any contractual mid-contract price rise as a fixed pounds-and-pence amount at the point of sale, banning the previous CPI-linked formula on new contracts. Existing contracts (signed before January 2025) retain their CPI+3.9% terms.

For existing-contract customers, the maths: with CPI assumed at 2.5%, the annual rise is +6.4%. On a £55/month contract, that's +£3.52 per month each year. Cumulative impact over a 24-month deal: £85–£105 above headline.

Strategy if signed pre-Jan-2025: track your effective rate after each annual rise. Budget for the next rise. Compare against current new-style fixed-price SIM-only deals — switching often saves the entire price-rise impact for the remaining term.

Bundled mobile contracts often include insurance worth £8–£15/month embedded in the price. Standalone phone insurance from third-party providers (Protect Your Bubble, gadget cover via home insurance, AppleCare+) typically costs £5–£10/month for similar cover.

Most home contents insurance can cover a phone "out of the home" if you add personal possessions cover (typically +£20–£40 to annual premium for £1,500 of cover, including phones, jewellery, laptops). For a household with 2–3 phones, this is usually cheaper than per-device insurance.

Check exclusions: many policies don't cover lost-without-trace claims, only theft and accidental damage. AppleCare+ for iPhone covers accidental damage (£79 excess for screen, £179 for other) and battery service. Decide based on your clumsiness probability and replacement budget.