iD Mobile and SMARTY both run on Three's network, but they're owned by very different companies. iD Mobile is a trading name of Currys, the electronics retailer. SMARTY is owned by Three itself, now part of VodafoneThree. Both sell low-cost SIM only plans with no scheduled price rises, so the differences are in contracts, credit checks, roaming, extras and one detail of coverage.
How do iD Mobile and SMARTY 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 |  SMARTY |
|---|---|---|
| Owned by | Currys | VodafoneThree |
| Runs on | Three's network | Three's network, plus Vodafone masts where they're shared |
| SIM only from | £6 a month | £6 a month |
| Cheapest unlimited data | £14 a month | £17 a month |
| Capped data plans | 8GB to 300GB, plus unlimited | 16GB to 200GB, plus unlimited |
| Contracts in our deals | 30-day, 12 months and 24 months | 30-day |
| 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 12GB a month from your allowance. |
| eSIM | Yes. QR code by email; manage it in the app or your online account. | Yes. Available straight away at sign-up; instant swaps from the dashboard. |
| Leaving early | 30-day: nothing. 12 or 24 months: up to the charges left, less iD's avoided costs. | Nothing. Every plan is 30-day rolling. |
| Deals | See iD Mobile deals | See SMARTY 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. Vodafone and Three masts are shared only at sites where sharing has been switched on: 10,000 of them by April 2026, according to Vodafone.
Is coverage the same on iD Mobile and SMARTY?
Mostly. iD says "iD runs on the Three network", and SMARTY says Three and SMARTY "share the same network". Ofcom's January 2026 figures for Three show 4G reaching 96.6% of premises indoors and 85.0% indoors in rural areas, with 5G at 75.9% of premises outdoors.
The difference is mast sharing. Since the Vodafone and Three merger, the two networks have been switching on shared masts, and Vodafone names SMARTY among the brands that can use them. That covered 10,000 sites by April 2026. iD Mobile isn't on Vodafone's list, so we don't assume iD customers get the same access.
In most places the signal will be the same. Where Three is weak and Vodafone is strong, SMARTY may connect where iD can't. Check your postcode on our mobile coverage map.
Which is cheaper, iD Mobile or SMARTY?
When we checked on 23 September 2026, iD was cheaper for unlimited data. Its unlimited plan cost £15 a month on a 30-day plan, or £14 on a 12-month contract. SMARTY's unlimited plan cost £17 a month, rolling. Over a year, that's £180 or £168 with iD against £204 with SMARTY.
At the cheap end they're close. Both started at £6 a month, with 25GB of data on iD's rolling plan and 18GB on SMARTY's. Promotions move these figures often, so compare the plan you'd keep. Our data allowance guide helps you pick a size.
Do you have to sign a contract?
SMARTY doesn't use contracts. Every plan is 30-day rolling, and SMARTY sums it up as "Cancel or change plans anytime. No contracts, no credit checks and no surprises at the end of the month".
iD sells 1-month, 12-month and 24-month SIM plans. Its rolling plans often come with as much data as its contracts for the same price, so committing doesn't always save you anything. If you do take a contract and leave early, iD's terms charge the monthly price for the months left, less its avoided costs. Text INFO to 85075 to check your figure.
Can the price go up?
Neither schedules a rise. iD's SIM page promises "No annual price rises" on its SIM plans. SMARTY says: "We don't do annual price rises with our rolling one month plans". None of either network's deals in our feed carries a scheduled rise. Our price rise guide covers the rules if that ever changes.
Will either run a credit check?
Here they differ. iD says: "For a Pay Monthly SIM only deal, you will need to pass a credit check". SMARTY says: "Because our SMARTY SIM-only deals are paid up-front on a rolling monthly plan, we do not require you to have a credit check".
If you'd rather avoid a search on your credit file, SMARTY gets you onto Three's network without one.
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. SMARTY lets you use up to 12GB of your allowance in the EU, with unlimited UK and EU calls and texts.
For trips beyond Europe, or heavy data use abroad, iD goes further. For a week in Spain on a light plan, both cost nothing extra. Our EU roaming guide compares every network.
What extras does each network add?
iD's Data Rollover is free on every plan, moving unused data into the next month. Bill Capping lets you limit out-of-plan charges from the app. iD Perks adds discounts from big-name brands, alongside a refer-a-friend scheme and a student discount.
SMARTY's standout extra is Group plans. Bring 2 to 8 plans together and save 10% on each. SMARTY also says you can "tether and hot-spot all of your data with no speed caps" in the UK, and offers referral gift cards of up to £20.
For a household with several phones, SMARTY's group discount adds up. For one person whose usage varies, iD's rollover is the more useful feature.
How does customer service compare?
Neither is built around a call centre. iD's contact page lists live chat, where a chatbot hands you to an adviser, plus an automated phone service, its app and a community forum. SMARTY offers a 24/7 chatbot, human chat from 8am to 8pm, email and a community forum.
Ofcom reports on iD but not SMARTY, which falls below the market-share threshold for its reports. iD recorded 3 complaints per 100,000 customers from January to March 2026, against an industry average of 2, which Ofcom treats as comparable. There's no equivalent Ofcom figure for SMARTY, so we don't compare one.
Why you might choose iD Mobile
- You want the lowest price on unlimited data, rolling or on contract.
- You travel beyond Europe, or use a lot of data abroad.
- You'd use free data rollover or iD Perks.
- You'd like the option of a 12 or 24-month plan.
Why you might choose SMARTY
- You'd rather avoid a credit check.
- You want the extra reach of shared Vodafone masts.
- You'd bring several SIMs together for 10% off each.
- You never want a contract.
How do you switch between iD Mobile and SMARTY?
Both use Three's masts, so your signal should change little. Text PAC to 65075 from your current phone and the code arrives within a minute. Give it to your new network, and the switch completes within one working day under Ofcom's rules. Our switching guide covers each step.
Leaving SMARTY costs nothing. Leaving an iD contract early can cost up to the charges left; our mobile exit fee calculator gives an upper estimate.
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 SMARTY's plan pages, Group plans, roaming page and credit check page, on 23 September 2026. Network sharing figures come from Vodafone's explainer. Complaints figures come from Ofcom's complaints data.