Everything You Need to Know About SIM-only Deals

Including how to compare plans and make the most of your data.

What Is a SIM Only Deal? Explained

A SIM only deal is a mobile phone contract that provides just the SIM card and a mobile service — including data, calls, and texts — without a new handset. This is perfect for people who:

• Already own a phone and want to keep using it.
• Prefer to buy phones outright or second-hand. Olimit’s editors favourite way to save money.
• Want to avoid monthly phone repayments bundled with their plan.

With SIM only, you pay a monthly fee for your allowance but keep full control over your device choice.

Why Are SIM Only Deals So Popular?

The popularity of SIM only deals has skyrocketed in recent years, mainly because:

• Smartphone prices have soared. Phones can cost £700-£1200+, so many users want to spread out costs or buy used phones.
• People want flexibility. Short-term rolling contracts let you switch networks easily without penalties. Perhaps you want to test wether a specific network has signal in your area.
• Data demands keep growing. SIM only plans often include generous or unlimited data at better prices than pay-monthly contracts.

Why Choose Olimit Over Buying Directly From Network Providers?

At Olimit, we negotiate and curate exclusive deals that often give you lower prices than buying straight from the network provider. Here’s a recent example that shows how much you can save by choosing Olimit:

Real Customer Example

A customer recently purchased a 120GB Three Mobile deal for £12 per month via Olimit, while the same deal costs £18 per month on Three’s official site. That’s a £6 monthly saving, adding up to £72 saved in just one year.

Even Bigger Savings

The customer realised the value and took out another exact same deal through Olimit for a loved one, saving another £72. That’s £144 total saved, which means effectively they got 2 full plans for the price of 1 when compared to buying directly from the network!

What Does This Mean for You?

• Better prices on the exact same plans.
• Multiple deals for less — great if you want plans for family or friends.
• No compromise — same coverage, same data, just cheaper.
• Trusted service — your information is managed directly by the network, ensuring you receive the best deal effortlessly.

Types of SIM Only Deals

Let’s break down the main types so you know what to expect:

1. Rolling Monthly Contracts aka – No contract
   • No fixed term.
   • Cancel anytime.
   • Perfect for flexibility and testing networks.
2. Fixed-Term Contracts (12 – 18 – 24 months)
   • Often cheaper monthly rates for committing.
   • Early exit fees may apply if you leave early.
   • £1-2 yearly increase each April.
3. Data-Only SIMs
   • No calls or texts, just data.
   • Used in tablets, dongles, mobile hotspots, and laptops.
4. eSIM Only Plans
   • Digital SIM built into your phone.
   • Activation by scanning a QR code — no physical SIM card needed.
   • Supported on newer devices like iPhone 11+, Google Pixel 3+, Samsung Galaxy S20+ and above.

How to Choose the Best SIM Only Deal for Your Needs

Step 1: Calculate Your Data Usage

Look at your current phone usage over the last 3 months. How much data do you use monthly? Do you stream videos? Use social media heavily? Play games? Have Wi-fi at home? This helps pick the right plan size.

Step 2: Decide on Contract Length

• Want no strings? Choose rolling monthly no contract deal. Look for in the deal listings.
• Want the cheapest monthly rate? Look for 12 – 18 or 24-month deals.

Step 3: Check Network Coverage and Speed

Use network coverage maps from Ofcom and check real user speed tests on websites like Opensignal or RootMetrics. Coverage varies between rural and urban areas.

Step 4: Compare Deals Side-by-Side

Use price comparison sites like Olimit.co.uk. Filter by data, contract length, and price. Olimit has made it easy to visually see all that is necessary.

Step 5: Look for Added Extras

Some plans include free streaming subscriptions, international roaming, hotspot tethering, rollover data or some really cool perks.

Top UK SIM Only Providers (and What Makes Them Special)

Emilie, 24 — The Frequent Traveler

“I switched to a SIM only plan on Three for £12/month with 120GB data. I kept my old iPhone 15 and save over £30 monthly compared to my old contract. I use Netflix and Spotify daily and never run out of data!”

James, 40 — The Frequent Traveler

“I travel a lot for work, so I got an O2 SIM only plan with roaming in over 80 countries. It’s cheaper than buying local SIMs everywhere, and I keep my UK number.”

Aisha, 19 — The Student

“I love VOXI because it doesn’t count my TikTok or Instagram usage against my data. I only pay £10 a month on a rolling contract, so I can cancel anytime.”

How to Switch to a SIM Only Plan (Step-by-Step)

1. Check your current contract: Find your contract end date and look out for any early termination fees. Sometimes, if you call your provider and explain you’re experiencing poor signal, you might be able to avoid these fees. Olimit editor Andy went through the same issue: “Nobody should have to deal with the frustration of poor signal for a service they’re paying for.”
2. Get your PAC code: Text PAC to 65075 from your current phone to get a porting code.
3. Choose your new plan: Use Olimit or other comparison tools.
4. Order your SIM card: Usually free or delivered next day. Instant if eSim.
5. Activate your SIM: Insert the new SIM and follow activation instructions. Use QR code for eSIM.
6. Keep your number: Provide your PAC to the new provider so your number transfers. This usually completes within 1-2 days.
7. Enjoy your new plan! 🥳🎉

SIM Only vs Pay Monthly Contract — Which Is Better?

How Much Can You Really Save With SIM Only?

Example:

• Pay Monthly iPhone 16 deal: £50/month for phone + data.
• SIM Only Unlimited GB plan: £16/month.

Over 24 months: Pay Monthly costs £1200, SIM only costs £384 — saving £816 total! This money can be put toward buying the phone outright or saving for other things.

International Use and Roaming with SIM Only Plans

Many SIM only plans include free roaming in the EU and beyond, but the details vary: Look for  in the deal listings.

What Is eSIM and Why Is It the Future of SIM Only?

• eSIM is an embedded SIM card that lives inside your device, no physical card needed.
• Activation is instant — just scan a QR code from your provider.
• Multiple profiles can live on one phone, great for travel or business/personal lines.
• Supported on most flagship devices since 2019.
• Providers like EE, Vodafone, Three, O2 and the networks like Lebara, Lyca, Voxi using their infrastructure offer eSIM plans as well.
• eSIM makes switching providers or plans simpler and quicker than ever.

Top Tips to Maximise Your SIM Only Deal

• Use Wi-Fi when possible to save your mobile data.
• Monitor your usage monthly using your provider’s app or phone settings.
• Choose unlimited data if you stream a lot.
• Consider dual SIM or eSIM for travel plans.
• Check for discounts if you’re a student, employee, or part of a loyalty scheme.
• Don’t be afraid to switch providers for a better deal — you’re in control!

Summary: SIM Only Deals Are Ideal If You…

• Want to keep your current phone.
• Prefer flexible contracts without long commitments.
• Want a cheaper monthly cost compared to phone + plan bundles.
• Value data freedom and control.
• Are happy managing your own phone purchase.

If that sounds like you, explore SIM only deals today on Olimit.co.uk to find the best plans tailored for your needs