- Status
- Updated daily
- Total deals tracked
- 552
- Networks tracked
- 21
- Last snapshot
- 18 May 2026
Written by Phil Brown
Founder, SIM Only Finder. Former Three UK retail manager with more than a decade building consumer comparison platforms. About Phil Brown
What the SIM Only Price Index tracks
The SIM Only Price Index draws on live deal data collected by SIM Only Finder across 21 UK networks and MVNOs. Every deal listed on the site feeds into the index, giving us a dataset that reflects actual available prices rather than advertised headline rates.
We track average monthly cost by data allowance tier across all contract lengths: 30-day rolling, 12-month, and 24-month. Prices are sourced directly from network and MVNO listings and the index is updated daily.
The index began tracking daily snapshots in April 2026. Historical month-by-month data will build automatically from that point.
Average SIM only prices by contract length
Compare average prices across different contract lengths.
| Data tier | Average | Lowest | Highest | Deals |
|---|---|---|---|---|
| Under 10GB | £8.51 | £3.90 | £30.00 | 37 |
| 10GB - 50GB | £11.20 | £5.90 | £33.00 | 53 |
| 50GB - 100GB | £12.97 | £7.00 | £35.00 | 31 |
| 100GB - unlimited | £17.77 | £8.95 | £37.00 | 48 |
| Unlimited | £26.41 | £15.00 | £47.00 | 28 |
| Data tier | Average | Lowest | Highest | Deals |
|---|---|---|---|---|
| Under 10GB | £10.37 | £3.50 | £27.99 | 16 |
| 10GB - 50GB | £10.59 | £5.95 | £30.99 | 64 |
| 50GB - 100GB | £10.67 | £7.95 | £17.00 | 51 |
| 100GB - unlimited | £15.78 | £9.95 | £34.99 | 54 |
| Unlimited | £22.46 | £15.00 | £41.99 | 23 |
| Data tier | Average | Lowest | Highest | Deals |
|---|---|---|---|---|
| Under 10GB | £10.50 | £3.00 | £24.99 | 13 |
| 10GB - 50GB | £14.27 | £5.95 | £39.00 | 28 |
| 50GB - 100GB | £12.48 | £7.95 | £24.00 | 24 |
| 100GB - unlimited | £19.81 | £10.00 | £47.00 | 57 |
| Unlimited | £29.70 | £15.00 | £56.00 | 25 |
Which networks have raised prices
Mid-contract price rises are now a standard feature of the UK mobile market. O2 applied a rise of up to £2.50 per month in April 2026, the largest we have tracked from a major network since Ofcom tightened its mid-contract guidance. Customers on O2 rolling contracts can switch without penalty.
How to use this data to find a better deal
If your current monthly cost is above the average for your data tier and contract length shown above, you are likely overpaying relative to what is currently available on the market.
The quickest way to act on that is to check whether you are on a rolling 30-day contract or a fixed term. If you are on a rolling contract, you can switch at any time with no exit fees. If you are on a fixed-term plan and your network has applied a mid-contract price rise, you have the right to exit without penalty within 30 days of being notified. Our PAC code guide explains how to keep your existing number when switching networks.
Editorial policy
Phil Brown, founder of SIM Only Finder, writes and maintains this page using live deal data collected across 21 UK networks and MVNOs. Pricing data is sourced directly from network and MVNO listings and updated daily. Phil's monthly commentary reflects his own analysis based on his experience in the UK mobile industry. Always confirm current pricing directly with your chosen network before signing up.
Ofcom-accredited price comparison
SIM Only Finder is accredited by Ofcom, the UK's independent regulator for communications services. Accreditation is awarded to comparison sites that meet Ofcom's standards for accuracy, transparency, and impartiality.
This means the deals you compare here are checked for accuracy, presented without bias toward any network, and reflect the actual cost you would pay. We do not promote deals based on commission earned.
Phil Brown's commentary
Phil Brown
May 2026
Prices have been broadly stable since April, but a few trends are worth noting. The 50GB to 100GB tier has softened across all contract lengths. The 30-day rolling average has dropped from £13.34 to £12.97, and 12-month plans in that tier now average £10.67. For anyone using moderate amounts of data, this tier continues to offer the strongest value relative to its allowance.
The 24-month 10GB to 50GB average has also fallen by over £1.50 since April, now sitting at £14.27. The flexibility premium we flagged in April remains small. In the 10GB to 100GB tiers, the saving from committing to 12 months over a rolling contract is modest, and the ability to switch without notice is worth more than the price difference suggests.
Unlimited pricing has barely moved. The 30-day rolling average of £25.65 and 12-month average of £22.46 are consistent with last month, suggesting the unlimited tier has found a floor for now.
Phil Brown
April 2026
In the under 10GB tier, 30-day rolling plans are currently cheaper on average than 12-month contracts, at £9.03 versus £10.33. That is the reverse of what you would normally expect. It reflects strong MVNO competition for flexible low-data plans and means there is little reason to commit to a 12-month deal at that allowance level right now.
O2's April rise, up to £2.50 per month, is the largest we have tracked from a major network since Ofcom tightened its mid-contract guidance. If you are on an O2 rolling plan, you can leave without penalty and there are unlimited deals available today for less than O2's post-rise price.