SIM-Only Mobile Prices 2026-2031: Confirmed Costs and Future Projections

SIM-Only Mobile Prices 2026-2031: Confirmed Costs and Future Projections

What's happening

UK mobile networks are raising SIM-only prices from April 2026. In January 2026, many mid-range SIM-only deals (roughly 50-100GB) are advertised around £8-£12/month, with £10/month a common new-customer price point on comparison sites.

The catch: many plans include mid-contract price rises, so people who don’t switch or renegotiate often see monthly costs step up by around £1.50-£2.50/year.

In this guide we use £10/month as a baseline and show how different pricing models change what you pay between 2026 and 2031.

From 1 April 2026, every major network will increase prices, but the amount varies by provider. Some brands (for example Smarty, and selected iD Mobile plans) advertise price-lock guarantees with zero increases during the minimum term. Others use tiered or flat increases.

Confirmed vs projected: Networks must disclose mid-contract rises in pounds and pence when you sign, so we treat April 2026-April 2029 as confirmed. Anything beyond 2029 is a scenario, not a commitment.

What this means for your mobile bills

The maths is simple, but the outcomes are big. If you only compare the headline monthly price, you can miss hundreds of pounds in long-run cost.

• Price-lock at £10/month: £720 over six years
• EE/O2-style flat rises (+£2.50/month each April): £1,350 over six years
• Difference: about £630 more if you stay on the flat-rise path

In other words: price increases matter more than the intro offer if you keep the same plan for years.

In April 2026, the increase you feel immediately is typically in the ~£11-£30 per year range (depending on provider and plan). The bigger question is what your monthly cost becomes by 2028-2031 if you don’t review your contract.

Also: if you’re on a handset bundle, switching to SIM-only at renewal can still save meaningful money. Handset contracts commonly cost £300-£500/year, versus £120-£240/year for many SIM-only use cases.

Who is affected

This analysis applies to UK households with mobile phones on SIM-only contracts and people considering a switch from handset bundles.

• New customers (Jan-Mar 2026): Your network choice now determines savings of £200-£630 over six years
• Existing pre-2025 SIM-only customers: You're likely on CPI + 3.9% pricing. Compare this with new price-lock plans at renewal
• Handset contract customers: You're paying 2-4x more than SIM-only users. Switching at renewal saves money, even with 2026 rises
• Budget-conscious users: Price-lock plans protect against future shocks but may cost 5-10% more upfront

What you can do now

• If you’re taking a new SIM-only deal (Jan-Mar 2026): don’t just pick the cheapest intro price. Prefer providers with clear, disclosed increases and consider price-lock or tiered models over flat +£2.50/month rises.

• If you want a faster way to compare: tools like Taupia can help you sanity-check whether you’re overpaying and when it’s worth switching.

• If you’re on an older pre-2025 contract: check your contract start date. Many older plans use CPI + 3.9% clauses, which compound. At renewal, compare your projected costs with today’s price-lock and fixed-increase options.

• If you’re on a handset contract: compare your current monthly bill with SIM-only deals for your usage. Even with 2026 rises, moving to SIM-only at renewal can cut total cost materially.

• If you want flexibility: a 30-day rolling SIM can cost a little more than a 12-month deal, but it makes it much easier to switch when prices jump.

Methodology: Confirmed vs. Assumed Data

What we know with certainty (through April 2029)

Since 1 January 2025, Ofcom requires networks to disclose mid-contract price increases upfront when you sign. This means April 2026-2029 increases are confirmed and locked in for new contracts.

What we reasonably project (April 2030 to December 2031)

Increases beyond April 2029 are not yet officially announced. We extrapolate 2030 to 2031 costs as scenarios based on four factors:

1. Regulatory inflection point: spectrum policy and renewal/auction cycles can materially change network cost bases around the end of the decade.
2. Historical precedent: Networks have typically passed most incremental spectrum and wholesale cost increases into consumer tariffs within about 12 to 18 months of policy changes.
3. Inflation forecasts: the Office for Budget Responsibility expects inflation to trend back toward low single digits over the medium term.
4. Network behaviour patterns: UK networks have implemented annual price increases every year since around 2014, usually at or above the inflation rate, even in periods of regulatory scrutiny.

All assumed 2030-2031 figures in this article are clearly labelled as “Assumed” in tables, and should be treated as scenarios, not commitments.

Pricing scenarios: 2026-2031 (confirmed to 2029, assumed thereafter)

All scenarios start from a £10/month mid-range SIM-only plan.

To keep comparisons clean, the tables below treat each row as a contract year starting in April (for example, “2026” means Apr 2026-Mar 2027). Where 2030-2031 appears, it is assumed, not confirmed.

Scenario 1: Price-lock guarantees (0% cumulative increase through 2031)

Some providers, such as Smarty and certain iD Mobile plans, offer explicit price-lock guarantees that prevent any mid-contract price increases during the minimum term.

Six-year total: £720.00 (baseline)

Scenario 2: Tiered increases (54% cumulative increase by 2031)

Three applies tiered increases by data allowance. For an illustrative mid-range plan, we model an annual rise of +£0.90/month applied each April.

Six-year total: £946.80 Difference versus price lock: about £226.80 more (~32% higher)

Scenario 3: EE-style fixed increases (150% cumulative increase by 2031)

EE and O2 apply a flat £2.50/month increase each April. This scenario extends that policy through 2031 on an assumed basis.

Six-year total: £1,350.00 Difference versus price lock: about £630.00 more (~88% higher)

Scenario 4: CPI + 3.9% inflation-linked (around 42% cumulative increase by 2031)

Older contracts signed before 1 January 2025 often carry CPI plus 3.9% clauses. For an illustrative path, we model a ~6% annual increase (CPI ~2% plus 3.9%, rounded).

Six-year total: £887.16 Difference versus price lock: about £167.16 more (~23% higher)

Six-year comparison (all scenarios side by side)

Key insight: these are stay-put paths. If you reassess annually (or use rolling contracts), you can often keep closer to the best current acquisition prices, but if you don’t, the price-rise model you choose can dominate your long-run cost.

Network-specific price increase details (confirmed through April 2029)

For a typical mid-range user, the mid-contract increase can be anywhere from £0 (price-lock) up to about £2.50/month (around £30/year), depending on provider and plan.

The spectrum cost wildcard: April 2029 and beyond

One of the biggest uncertainties for 2030 and beyond is spectrum policy and network cost changes around the end of the decade.

• Current status: mobile networks operate under long-dated spectrum licences with renewal and auction cycles that can change costs.
• End-of-decade risk: if spectrum or wholesale costs rise materially, networks may build larger future increases into new contracts signed in 2028-2029.

For consumers, that could mean future contracts move toward larger fixed rises (or higher baseline prices), which is why our 2030-2031 rows are scenarios, not promises. If networks pass through more of their costs, real prices could end up materially higher than the assumed paths.

Related reading

• Loyalty Tax Calculator — See how much staying loyal costs across energy, broadband, and mobile bills over time.
• How We Calculate Savings — Understand the methodology behind our savings benchmarks.
• How Switching Works — Step-by-step guide to switching providers with Taupia.

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