Cheapest 30GB SIMs in the UK

To find the cheapest 30GB SIM available in our current selection, start with the live exact-30GB deals. Compare the normal price after promotions, the total payments over your intended period, and coverage before choosing. If you want flexibility, compare the 30-day options separately from 12- or 24-month commitments. A 40GB or 50GB deal can sometimes be cheaper than 30GB, while 20GB may be enough if you mostly use Wi-Fi.

Ready to choose? On the 30GB comparison page, narrow the offers to a suitable network and contract length, open Full plan details for the price schedule, then use that deal's View Deal link. The catalogue supplies the offers; this guide helps you judge the cost and avoid buying the wrong allowance.

What counts as the cheapest 30GB SIM?

Search results mix three different claims: a cheap first bill, a cheap standard renewal, and a cheap total cost over the period you intend to keep the SIM. Those are not the same thing. The minimum advertised amount can be a short introductory discount; a longer contract may appear cheaper but limit your ability to switch; and a plan offering more than 30GB may undercut the exact-30GB category.

A useful rule: choose the cheapest plan that meets your needs, not the lowest cost per gigabyte or the largest advertised allowance. Paying extra for 100GB you will never use is not automatically a bargain. On the other hand, rejecting a cheaper 50GB plan solely because you searched for 30GB makes little sense.

Exact 30GB or a 40GB or 50GB alternative?

The data allowance printed on a SIM offer is a selection criterion, not a guarantee of value. In our catalogue, exact-30GB plans sit alongside other data tiers whose prices and promotions move independently. So the right comparison has two stages:

1. Find the best exact-30GB option with the coverage, commitment and essential features you want.
2. Compare its total cost with the nearest suitable larger and smaller plans, under equivalent terms where possible.

Suppose, purely as an illustration, that Plan A offers 30GB for £9 per calendar month and Plan B offers 50GB for £10 per calendar month, with no promotions or price changes. Over twelve monthly bills, they cost £108 and £120 respectively. You pay £12 more for the larger allowance over that period. If your busiest ordinary month is 18GB, that extra data might be unnecessary. If you frequently exceed 30GB, paying the £12 could be a better decision than buying add-ons. If your extra-data charges on Plan A would exceed £12 over those twelve months, Plan B would cost less overall, assuming the same service and no other charges. These are hypothetical prices, not live offers.

The reverse is also possible: a larger plan may be cheaper at the time you shop. That is why a 50GB comparison belongs alongside the exact-30GB list. If you need much more than 50GB, do not force a 30GB choice; go to 100GB+ SIM deals instead.

When a 20GB SIM is the smarter cheap option

Look at your own consumption before paying for a nominal 30GB bundle. If your last three complete billing periods used 9GB, 12GB and 11GB, a reasonably priced 20GB plan gives substantial room for a similar month. You might still prefer 30GB for a planned commute or more video, but you do not need it simply because it looks like a popular middle tier.

Our mobile data usage guide covers estimating your allowance in detail, and the data usage calculator is useful if you have not tracked your history. For this purchasing decision, use your highest normal month, not just your average, and leave room for changes you genuinely expect.

Why a £6 headline can cost more than a £9 plan

The most common cheap-SIM mistake is treating the introductory price as the normal price. Consider two hypothetical calendar-month plans with the same data, coverage and features:

Although Plan A starts £3 cheaper, it costs £9 more over twelve calendar-month payments (£6 × 3 + £11 × 9, versus £9 × 12). If Plan A instead rose to £10 after month three, both totals would be £108 — still no saving from its cheaper opening price. All amounts are hypothetical, not quotations from a real provider. The calculation assumes no other charges or changes.

For a real deal, add each required payment, any upfront or activation charges and known contractual price increases. Then compare the offers over the same period, while noting how long each commits you. A 30-day card's displayed minimum-term cost may cover only its first renewal, whereas a 12- or 24-month contract total covers a much longer obligation; those numbers are not directly comparable. For UK consumer contracts entered into since 17 January 2025, Ofcom's rules require contractual price increases to be stated upfront in pounds and pence, rather than tied to unknown future inflation. That does not mean every tariff is guaranteed never to change price; a rolling package or a new deal after its term may work differently.

A 30-day bundle is not a calendar-month bill

A plan that actually renews every 30 days follows a different payment rhythm from one billed once per calendar month. To keep continuous cover for a full 365 days, you would need 13 paid 30-day periods: twelve cover only 360 days, and the thirteenth extends beyond the year. For example, at a hypothetical fixed £10 per payment, that is £130 paid versus £120 for twelve £10 calendar-month bills over the same year. The extra 30-day payment also buys cover beyond day 365; it is not a 13-month commitment. Not every plan described as 'monthly rolling' bills in exact 30-day cycles, so check the provider's renewal dates before comparing.

Also distinguish a rolling term from a genuine pay-as-you-go arrangement. A 30-day bundle may renew automatically using a balance or stored payment method. Look at what happens if payment fails, whether you must cancel before a specific date and whether unused data rolls over. These are important differences even when two plans quote the same price.

Which UK providers are worth considering for around 30GB?

There is no evidence-based permanent winner for every buyer. These are useful shortlists by need, not rankings of today's cheapest deals. Always match the recommendation to an actual live offer.

Lyca versus Lebara: when an included extra is worth more than extra GB

If you regularly call family overseas, data alone is a poor way to compare two 30GB SIMs. Lyca's current UK plans use EE-based coverage; Lebara's offers use Vodafone-based coverage. Both market international-calling benefits on qualifying plans, but the minutes, eligible destinations, number types and renewal conditions vary. A 30GB offer in our catalogue is not proof that every number in your contact list is covered.

Start with the current domestic-data and price comparison, then check whether the specific tariff's calling allowance actually works for your destination. If neither does, an ordinary lower-cost UK SIM plus a suitable calling option may be better. Our international-calling guide explains that separate choice. Do not select a partner just because it offers a headline international-minute figure.

1pMobile: more data can beat a strict 30GB search

For an EE-based alternative, our 1pMobile SIM comparison is worth checking even when you began by searching for 30GB. The relevant purchase may be a larger rolling bundle rather than an exact 30GB product. That makes sense only when its full renewal cost and permitted use compare well with the exact-30GB alternatives.

1pMobile is not automatically the cheapest because a bundle has a higher GB figure, and its ordinary Boost allowances should not be mistaken for inclusive overseas calling. If tethering or unusually heavy use is important, check the plan's permission and fair-use conditions rather than assuming that more GB always means fewer restrictions. For a narrower coverage comparison see EE-network SIM deals.

Do not overlook a cheaper non-partner offer

DealPriceCheck's 30GB catalogue also shows selected plans from operators that are not necessarily current affiliate partners. If a Talkmobile, spusu, iD Mobile or other listed deal is cheaper on the same comparison period and works better in your location, it deserves to win the comparison. The right commercial result comes from helping you pick a genuinely suitable SIM, not forcing a promoted provider into first place.

How important are coverage, roaming and eSIM for a cheap 30GB SIM?

Coverage comes before the lowest bill

A cheap plan is poor value if it regularly loses signal at home or on your commute. Use Ofcom's Map Your Mobile to compare predicted indoor and outdoor coverage and local performance, then check your chosen provider's current coverage information. Ofcom's results are a guide, not an indoor-performance guarantee. Two brands using the same physical network may still differ in speed tiers, services, support and available features.

For network-specific shopping, see our EE-network deals, Vodafone-network deals, Three-network deals and O2-network deals. Network availability and supported services can change as infrastructure evolves, so select the provider and actual offer rather than relying only on a familiar host-network name.

A 30GB UK allowance is not 30GB of EU roaming

Thirty gigabytes of domestic UK data says nothing by itself about what you may use abroad. A plan might include a smaller EU fair-use allowance, charge for certain destinations, or require an eligible package. If travel matters, compare the destination and overseas limit through our EU-roaming SIM deals before paying for extra domestic data. Similarly, included international calls from the UK are not the same benefit as roaming while abroad.

5G and eSIM are useful only when they fit your device and area

Some 30GB tariffs include 5G and eSIM, while others have different activation or device rules. A faster 5G connection does not make the same file intrinsically larger, but it can make higher-quality streaming and more downloads tempting. If you need immediate digital activation, look at eSIM deals, then check that your device and selected plan are eligible. Never assume the words '30GB' imply a particular 5G speed or eSIM entitlement.

What can 30GB actually cover?

Thirty gigabytes can be ample for someone who uses Wi-Fi at home and work, but limited for someone streaming frequently on mobile data. Avoid fixed 'hours per GB' claims across all apps: playback quality and settings matter much more than the app's name.

For a documented illustration, Netflix's data-usage guidance quotes up to 0.7GB per hour at Medium quality and 3GB per hour for HD at High quality. At those settings, ten hours of viewing could use up to about 7GB or 30GB respectively. These are Netflix playback settings, not universal rates for YouTube, TikTok, video calls or all phones. Downloads, background updates and a shared laptop hotspot can add to consumption.

Three practical checks beat a generic recommendation:

• Mostly Wi-Fi: if ordinary recent use is well below 20GB, price a 20GB plan before paying for 30GB.
• Regular mobile streaming: compare your highest-use month and the cost of larger bundles against the 30GB shortlist.
• Laptop hotspot or a broadband backup: include connected-device usage and consider our hotspot and tethering guide instead of relying on a phone-only estimate.

You can normally see historical usage in your provider's app. On an iPhone, Settings → Mobile Data/Cellular shows usage, although Apple's 'Current Period' counter does not necessarily reset with your bill. Android menu names vary; Google's Pixel usage guide explains the data-usage screen and warning settings. For the buying calculation, your provider's completed billing periods are the better reference when phone dates do not match.

Before you buy: a five-minute 30GB SIM check

1. Compare the current exact-30GB deal cards on networks that provide usable coverage where you need it.
2. Note each suitable offer's entire payment schedule, including introductory prices, later renewals, known increases, any upfront costs and the minimum commitment.
3. Open 20GB and 50GB to see whether a different allowance offers a lower total cost for your actual use.
4. If you travel, call abroad or need eSIM, check those benefits and restrictions on the exact plan, not the provider's general homepage.
5. Open Full plan details and follow the offer's existing View Deal link to the provider's checkout.

That keeps the decision connected to a current DealPriceCheck tariff, not a price frozen in an old article. The right deal has the lowest realistic cost for a plan that works for you, not necessarily the lowest cost per GB.

Frequently asked questions

What is the cheapest 30GB SIM-only deal in the UK?

There is no permanent cheapest operator: promotional first payments and ongoing prices can give different answers. Start with the live exact-30GB comparison and choose a suitable network. For a rolling plan, compare what you will pay after the promotion; for a 12- or 24-month plan, compare its full minimum-term cost and commitment. Do not treat the smallest first bill as the cheapest ongoing tariff.

Can I get a cheap 30GB SIM on a 30-day rolling plan?

Yes, 30-day and other flexible offers exist, but the lowest monthly price can vary. Compare rolling options against longer commitments and count the actual renewals during your intended period; 30 days is not a calendar month. See no-contract SIM comparisons.

Is a 50GB SIM sometimes cheaper than 30GB?

Yes. Promotions and operator pricing can make a suitable larger bundle less expensive. Compare exact-30GB deals with 50GB deals on the same network and equivalent payment terms before buying. Extra data is useful only if the rest of the plan works for you.

Is 30GB enough for Netflix or YouTube?

It depends on how often you stream over mobile data and at what quality. Netflix publishes substantially different usage figures for Medium and HD settings; another service may behave differently. Check your recent usage, then choose 30GB only if it covers a busy normal month.

Does a 30GB SIM include 30GB in Europe?

Not automatically. The domestic allowance and EU roaming entitlement can be different. Check the destination and fair-use limit on the exact tariff, or start with EU-roaming SIM comparisons.

Should I buy 30GB, 20GB or unlimited?

Use your measured usage and full price. An inexpensive 20GB plan may be sufficient if you're usually on Wi-Fi; 30GB can provide headroom; unlimited may make sense for sustained heavy use. Our data usage guide helps estimate demand, while unlimited deals are a separate live category.

How many 30-day renewals cover a full year?

If the tariff bills in exact 30-day periods, 13 payments are required to stay covered for 365 days, since 12 periods last 360 days. The last payment covers days beyond the year, and the bundle does not become a long contract. Check actual dates because some rolling offers renew monthly rather than every 30 days.

Bottom line: shortlist a 30GB offer only after checking its post-promotion price and network, then test whether 20GB meets your needs or 50GB delivers better total value. The live 30GB deals page is where the actual buying comparison belongs; this guide is how to avoid choosing the wrong bargain.

Editorial research reviewed 21 October 2026. DealPriceCheck compares selected UK offers; individual prices, promotions and plan terms can change. Check each offer's last-verified date and final provider terms before purchase. Some links may earn us a commission at no extra cost to you.