Question 1

What is the cheapest SIM only deal in the UK right now?

Accepted Answer

The cheapest SIM only deals in the UK start from around £1 to £5 per month for low data allowances (1GB – 5GB), typically from MVNOs such as Lebara, Giffgaff, or Smarty. Prices change frequently — compare live on Switch to see the cheapest available deal for your data amount today.

Question 2

Is a SIM only deal better than a phone contract?

Accepted Answer

If you already own a phone you are happy with, a SIM only deal is almost always cheaper. You are not paying off a handset, so the monthly cost is lower. The only time a phone contract may work out cheaper is when a network runs a subsidised promotion on a specific handset — always check the total cost over the contract length before deciding.

Question 3

Can I get a SIM only deal with no credit check?

Accepted Answer

Yes. Many 30-day rolling SIM deals and MVNO plans do not require a credit check. Giffgaff, Smarty, Lebara, and 1pMobile are examples of providers that offer plans without a formal credit check. Check the provider's terms before signing up if this is important to you.

Question 4

What is an MVNO?

Accepted Answer

An MVNO (Mobile Virtual Network Operator) is a mobile provider that does not own its own network infrastructure. Instead, it uses the signal from one of the four main UK networks (O2, Vodafone, Three, or EE) and sells its own plans at lower prices. You get the same underlying coverage at a cheaper monthly cost. Examples include Giffgaff, iD Mobile, Smarty, and Lebara.

Question 5

Can I switch SIM deals without changing my number?

Accepted Answer

Yes. Text PAC to 65075 (free) to get your number transfer code. Provide this to your new provider when signing up. Your number moves across within one working day, usually with only a few minutes of downtime.

Question 6

What happens to unused data on a SIM only deal?

Accepted Answer

It depends on the provider. Some networks reset your data allowance at the end of each month, meaning unused data is lost. Others — including Smarty and iD Mobile — offer data rollover, carrying unused data into the next month. Check the plan's terms when comparing if data rollover matters to you.

Question 7

Can I get a cheap SIM only deal with 5G?

Accepted Answer

Yes. 5G is now available on SIM only deals at no extra cost from most UK networks and MVNOs. You need a 5G-capable handset to use it. If your phone supports 5G, filter for 5G plans when comparing on Switch — many are available for under £15/month.

Question 8

What is a PAC code and how do I get one?

Accepted Answer

A PAC (Porting Authorisation Code) is the code you need to move your existing mobile number to a new network. Text PAC to 65075 (free). You receive the code by text within one working day. Provide it to your new provider at the point of sign-up to transfer your number automatically.

Question 9

How long does it take to switch SIM?

Accepted Answer

The comparison and sign-up process on Switch takes a few minutes. If you are porting your number using a PAC code, the number transfer typically completes within one working day, with only a brief interruption. If you are taking a new number (no PAC), your new SIM activates as soon as it arrives — or instantly if you choose an eSIM.

Question 10

Are there any SIM only deals without annual price rises?

Accepted Answer

Yes. Several providers — including iD Mobile, Smarty, and Lebara — commit to no annual mid-contract price rises on SIM only deals. When comparing, look for this commitment in the plan terms. Switch flags deals with and without mid-contract price rises so you can compare the true cost. Compare Cheap SIM Only Deals UK — Takes 2 Minutes If you have not compared your mobile plan in the last 12 months, you are almost certainly overpaying. The cheap SIM only deals UK market has never been more competitive — prices have dropped and data allowances have grown. There is no paperwork, no engineer visit, and switching takes a few minutes online. Switch compares every available SIM only deal by total monthly cost — no ranked-by-commission results, no cached pricing. Compare today, find your cheapest plan, and switch in minutes.

Compare cheap SIM-only deals

List of deals (222)

Mozillion Pay Monthly Plus 10GB 24 months (£62.50 upfront + £2.50/mo)

Mozillion Pay Monthly Plus 30GB 24 months (£68.75 upfront + £2.75/mo)

Mozillion 1GB SIM Only, 12-month

Mozillion 80GB SIM Only, 24-month

Mozillion Pay Monthly Plus 100GB 24 months (£81.25 upfront + £3.25/mo)

Mozillion 3GB SIM Only, 24-month

Mozillion 210GB SIM Only, 24-month

Mozillion 3GB SIM Only, 12-month

Mozillion 260GB SIM Only, 24-month

Mozillion Pay Monthly Plus 310GB 24 months (£100 upfront + £4/mo)

Mozillion 3GB SIM, £4.50/mo, 1-month rolling

Lebara 5GB SIM, £4.50/mo, 12 months

Lebara 5GB SIM, £5/mo, 1-month rolling

Mozillion 10GB SIM, £5.90/mo, 1-month rolling

giffgaff SIM Only on golden goodybag with Unlimited mins & texts…

giffgaff SIM Only on goodybag 1GB with Unlimited mins & texts…

Mozillion 10GB SIM, £6/mo, 24 months

iD Mobile SIM Only on 5G 25GB (1 Month contract) with Unlimited mins…

Smarty 18GB SIM, £6/mo with affiliate voucher, 1-month rolling

iD Mobile SIM Only on 5G 12GB (12 Month contract) with Unlimited mins…

iD Mobile SIM Only on 5G 15GB (24 Month contract) with Unlimited mins…

iD Mobile SIM Only on 5G 15GB (1 Month contract) with Unlimited mins…

Mozillion 10GB SIM, £6.50/mo, 12 months

SIM Only 15GB

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