News · 11 November 2026
iD Mobile's Black Friday half-price SIMs: what they really cost
Until 1 December 2026, iD Mobile is giving new customers half-price line rental on selected SIM-only plans: 3 months on 12-month plans and 6 months on 24-month plans. iD SIMs have no annual price rises, so the sums are simple. The 24-month 100GB plan works out at £8.75 a month over the contract, and 12 months of unlimited data at £15.75 a month.
Quick answer: iD Mobile's Black Friday offer (4 November to 1 December 2026) halves the price for the first 3 months of selected 12-month SIM plans, or the first 6 months of 24-month plans. With no April rises, the true monthly cost is £8.75 for 100GB (12 or 24 months), £10.50 for 150GB, £12.25 for 200GB or 250GB and £15.75 for unlimited (12 months). It only applies if you buy directly on idmobile.co.uk.
By The SimSift team · Published · Figures checked 11 November 2026
Lowest average
100GB, 24 months
£8.75 /month true cost
£5 for 6 months, then £10
Shorter commitment
100GB, 12 months
£8.75 /month true cost
£5 for 3 months, then £10
Unlimited data
Unlimited, 12 months
£15.75 /month true cost
£9 for 3 months, then £18
What changed
iD Mobile's promotion terms say: "Purchase selected 12 or 24 month SIM-only plans and receive either 3 or 6 Month Half Price Line Rental", and that the promotion "will run between 04/11/26 until 01/12/26". After the half-price months you pay the standard monthly price for the rest of the contract. iD also says its SIM-only plans "are not subject to annual CPI or RPI price increases" (iD Mobile).
Who it affects
- New iD Mobile customers aged 18 or over who live in the UK. A credit check applies.
- People happy to sign up for 12 or 24 months in return for a lower average price.
- Only if you buy directly on idmobile.co.uk. iD's terms say the offer doesn't apply if you start through a comparison site, an affiliate or telesales.
What it costs (true monthly cost)
True monthly cost is the total you pay over the contract divided by the number of months. There are no price rises to add.
| Plan | Half price | Then | Total over contract | True monthly cost |
|---|---|---|---|---|
| 12 months, 100GB* | £5 for 3 months | £10 | £105 | £8.75 |
| 12 months, 150GB | £6 for 3 months | £12 | £126 | £10.50 |
| 12 months, 200GB | £7 for 3 months | £14 | £147 | £12.25 |
| 12 months, unlimited | £9 for 3 months | £18 | £189 | £15.75 |
| 24 months, 100GB | £5 for 6 months | £10 | £210 | £8.75 |
| 24 months, 150GB | £6 for 6 months | £12 | £252 | £10.50 |
| 24 months, 250GB | £7 for 6 months | £14 | £294 | £12.25 |
*On 11 November 2026, iD's plan card and its basket both showed 100GB for this plan. The table in iD's promotion terms lists 90GB. The price is the same either way, so check the allowance in your basket.
Things to watch:
- £5 isn't what you pay for most of the contract. From month 4 (12 months) or month 7 (24 months) you pay the full price.
- The 12-month 100GB plan has the same average price as the 24-month one, with half the commitment.
- Roaming in 50 destinations is included, with a 30GB fair-use limit.
- iD runs on the Three network (now part of VodafoneThree). Check coverage at your postcode first.
Questions people ask
How long does iD Mobile's Black Friday half price last?
iD's promotion terms say it runs from 4 November 2026 until 1 December 2026. You get 3 months at half price on selected 12-month SIM-only plans, or 6 months at half price on selected 24-month plans, then the standard price for the rest of the contract.
Is the 12-month £10 iD plan 90GB or 100GB?
When we checked on 11 November 2026, iD's plan card and its basket both showed 100GB for £5 a month for 3 months, then £10 a month. The table in iD's promotion terms lists 90GB for the same plan. The price is the same either way, so check the data allowance in your basket before you buy.
Do iD Mobile SIM prices go up in April?
No. iD says its SIM-only plans are not subject to annual CPI or RPI price increases, so the true monthly cost is just the total you pay divided by the months.
Can I get the iD half price through a comparison site?
No. iD's terms say the offer is only available if you start on idmobile.co.uk, and not if the sales journey started through an affiliate, comparison site or telesales. Our links go straight to iD with no tracking.
What to do
- Compare the true monthly cost, not £5. Unlimited at £15.75 is well below O2's Black Friday unlimited, which works out at about £22.70 once its April rises are counted.
- Go direct. Start on idmobile.co.uk, or the half price won't apply.
- Check Three coverage where you live with Ofcom's Map Your Mobile.
- Switching is free: text PAC to 65075 to keep your number.
Compare on SimSift
Sources
- iD Mobile: SIM only deals and half-price promotion terms (primary)
- Ofcom: Map Your Mobile
- SimSift: O2 Black Friday SIMs (true cost £22.70, from O2's own pages, 10 November 2026)
Figures checked 11 November 2026 against iD Mobile's own page and basket. iD can change offers at any time.
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