iD Mobile and giffgaff both sell low-cost SIM only plans, but they run on different networks. iD Mobile is a trading name of Currys and, in its own words, "iD runs on the Three network". giffgaff is owned by Virgin Media O2 and runs on O2's masts. Both are cheap and neither schedules mid-contract rises, so the choice comes down to signal where you live, credit checks, data rollover and how far you travel.
How do iD Mobile and giffgaff compare at a glance?
The table pulls prices and price rises from our live deal feed, so it matches the deals on our comparison pages today. The roaming, eSIM and exit-fee rows come from each network's own pages.
| Feature |  iD Mobile |  giffgaff |
|---|---|---|
| Owned by | Currys | Virgin Media O2 |
| Runs on | Three's network | O2's network |
| SIM only from | £6 a month | £6 a month |
| Cheapest unlimited data | £14 a month | £14 a month |
| Capped data plans | 8GB to 300GB, plus unlimited | 2GB to 200GB, plus unlimited |
| Contracts in our deals | 30-day, 12 months and 24 months | 30-day and 18 months |
| Scheduled price rises | None scheduled on current deals | None scheduled on current deals |
| EU roaming | Included. 50 destinations, up to 30GB a month under its fair use policy (re-checked 23 September 2026). | Included. Up to 5GB, with top-up add-ons after that. |
| eSIM | Yes. QR code by email; manage it in the app or your online account. | Yes. Activation is app-only; there are no QR codes. |
| Leaving early | 30-day: nothing. 12 or 24 months: up to the charges left, less iD's avoided costs. | Monthly plans: nothing. 18-month plans: half the monthly price for each month left. |
| Deals | See iD Mobile deals | See giffgaff deals |
Live rows show the deals in our feed at the last refresh, not every plan a network sells. EU roaming was checked against each network’s own pages on 28 August 2026, eSIM on 26 August 2026, and ownership and exit terms on 23 September 2026.
Which has better coverage where you live?
That depends entirely on your area, because the masts are different. iD Mobile uses Three's network. giffgaff uses O2's. Nationally, Ofcom's January 2026 figures put them close: Three's indoor 4G reached 96.6% of premises against O2's 95.5%, and 85.0% against 82.0% indoors in rural areas. O2 led on outdoor 5G, at 86.2% against Three's 75.9%.
One detail matters for Three-based brands. Since the Vodafone and Three merger, some brands on those networks can also use the other network's masts where sharing is switched on. Vodafone's list of brands that benefit doesn't include iD Mobile, so we don't assume iD customers get that extra reach.
Check your own postcode on our mobile coverage map first. If one network is clearly weaker at home or at work, that should settle it before price does.
Which is cheaper, iD Mobile or giffgaff?
For unlimited data they're level on contract and apart on rolling plans. When we checked on 23 September 2026, both sold unlimited data for £14 a month: iD on a 12-month contract and giffgaff on an 18-month one. On a 30-day plan, iD charged £15 and giffgaff £20.
At the cheap end, iD's £6 rolling plan came with 25GB of data, while giffgaff's £6 rolling plan came with 2GB. iD's 30-day plans often came with as much data as its contracts for the same price, or more, so you rarely pay extra for the freedom to leave.
giffgaff's best value sits on its 18-month contracts, which it calls "our best value plans". Our data allowance guide helps you pick the right size before you compare.
Can the price go up?
Neither schedules a rise. iD's SIM page promises "No annual price rises" on its SIM plans, and none of its 66 deals in our feed carries a scheduled rise. giffgaff's deals page promises a "Price lock" with "no mid-contract price rises" on its 18-month contracts. Its general terms still keep a right to change prices with advance notice.
That's different from O2, Vodafone and Three, which add a set amount each April. Our price rise guide shows who raises prices and by how much.
Will either run a credit check?
This is one of the clearest differences. iD says: "For a Pay Monthly SIM only deal, you will need to pass a credit check". It adds that SIM only applications are more likely to pass than phone deals. giffgaff says: "They'll only carry out a credit check if you buy a phone on a contract with a loan". That covers its SIM plans, including 18-month contracts.
If your credit history is thin or you'd rather avoid a search on your file, giffgaff avoids the question altogether.
What extras does each network add?
iD has three worth knowing about. Data Rollover is free on every plan: unused data moves into the next month and gets used first. Bill Capping, also on every plan, lets you set a limit on out-of-plan charges in the app. And iD Perks offers discounts from big-name brands, alongside a refer-a-friend scheme and a student discount.
giffgaff's main extra is Payback. Members earn points for recommending friends, answering community questions and suggesting ideas. Each point is worth 1p, paid out in June and December as PayPal cash, credit or a charity donation. It also offers an optional spend cap, and it's a certified B Corp.
If your data use swings from month to month, iD's rollover smooths it out. If you'd rather earn a little back for helping others, giffgaff's Payback is the more unusual perk.
Which is better for travel?
iD includes roaming in 50 destinations, which iD says is more than any other UK network, with up to 30GB of data a month under its fair use policy. giffgaff includes EU roaming up to 5GB, then charges 10p for each extra MB, according to its plan pages.
For a heavy data user on holiday, that gap matters: 5GB can go in a few days of maps and streaming. Our EU roaming guide compares every network's caps and charges.
How does customer service compare?
Neither offers a traditional call centre as its main channel. iD's contact page lists live chat, where a chatbot passes you to an adviser, plus an automated phone service, its app and a community forum. giffgaff has no phone line; help comes through its online help hub, an AI assistant that hands over to agents, and its member community.
Ofcom's figures for January to March 2026 recorded 3 complaints per 100,000 iD Mobile customers and 1 for giffgaff, against an industry average of 2. Ofcom treats both as comparable with the average. In Ofcom's 2024 customer service survey, 94% of giffgaff customers were satisfied overall. Ofcom's sample of iD customers was too small to report a score.
Why you might choose iD Mobile
- Three's signal is stronger where you live, work or travel.
- You want a cheap rolling plan with plenty of data.
- You'd use free data rollover or iD Perks.
- You travel beyond Europe or use more than 5GB of data abroad.
Why you might choose giffgaff
- O2's signal, especially outdoor 5G, is stronger in your area.
- You'd rather avoid a credit check on your SIM plan.
- You want a written price lock on an 18-month plan.
- You like the member community and earning Payback.
How do you switch between iD Mobile and giffgaff?
This switch changes your network, so check coverage first. To keep your number, text PAC to 65075 from your current phone. The code arrives within a minute, and your new network completes the switch within one working day under Ofcom's rules. Our switching guide covers each step.
Leaving mid-contract can cost money on both. giffgaff charges half the monthly price for each month left on an 18-month plan. iD's terms charge the monthly price for the months left, less its avoided costs; text INFO to 85075 to see your exact figure. Our mobile exit fee calculator gives an upper estimate for iD.
Sources and how we checked
Prices, contract lengths and scheduled rises come from our live deal feed and refresh whenever the site updates. We checked iD Mobile's SIM deals page, Data Rollover page, roaming page and coverage page, and giffgaff's SIM deals page, terms and credit check help, on 23 September 2026. Service figures come from Ofcom's complaints data and Comparing Customer Service report.