Is 30GB of Data Enough?

30GB sits in the middle of the UK market and is the allowance most people end up needing. This guide explains what 30GB realistically covers, who it suits, and when stepping up or down makes more sense.

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Reviewed by: Phil Brown, founder of SIM Only Finder. Phil previously worked in UK mobile retail at Three UK, advising customers on SIM plans, contracts, and network choices. He has spent over a decade running consumer comparison platforms and reviews networks and SIM-only deals based on that hands-on industry background. About the author

Last reviewed: July 2026. Updated regularly to reflect current plan pricing, network changes, and roaming policies.

How we put this guide together

To put this guide together, we reviewed the plans offered at and around the 30GB mark across the main UK networks and MVNOs, checking how the tier is priced relative to smaller and larger allowances and comparing inclusive features directly against each network's published terms. Usage figures are estimates based on published app and network guidance, since actual consumption varies with video quality, handset, and how much content is cached rather than streamed.

Quick answer: is 30GB enough?

For most people, yes. 30GB comfortably covers everyday browsing, messaging, maps, music, and social media, with room for several hours of video a week away from Wi-Fi.

It stops being enough if you stream video daily on mobile data, commute for long periods without Wi-Fi, or regularly tether a laptop. In those cases the allowance runs out in the final week of the month, which is the usual pattern people notice.

What 30GB actually covers in a month

Put in concrete terms, 30GB is roughly equivalent to any one of the following across a month, assuming little else is competing for it.

• Around 30 hours of standard definition video streaming
• Around 10 hours of high definition video streaming
• Several hundred hours of music streaming
• Well over a hundred hours of video calling
• Effectively unlimited messaging, email, browsing, and navigation

In practice your month is a mixture of these rather than any single one. The useful way to read the list is that everything except video is close to irrelevant to the total. If 30GB is not lasting you, video streaming or autoplay in social apps is where it is going.

Who 30GB suits

30GB is the right allowance for someone with Wi-Fi at home and usually at work, who uses their phone freely through the day without thinking about it, and who watches some video on the move but not constantly. That describes a large share of UK users.

It also suits people who have previously run short on a 10GB or 15GB plan and want to stop monitoring their usage without paying for a large allowance they will not touch. The step from a small allowance to 30GB is usually a modest monthly increase, and it is the point at which most people stop thinking about data at all.

Best for: Average smartphone users who want to stop watching their data usage entirely, without paying the premium that 100GB or unlimited plans carry.

When 30GB is not enough

There are four situations where 30GB tends to fall short. The first is a daily commute without reliable Wi-Fi, where an hour of video each way adds up quickly. The second is regular tethering, because laptops consume far more than phones and a single software update can take several gigabytes.

The third is having no fixed home broadband, or unreliable broadband, so that the phone becomes the primary connection rather than a supplement. The fourth is heavy high definition or 4K video streaming, where three hours a week is enough to consume most of the allowance on its own.

If any of those apply, look at 100GB rather than a modest step up. The pricing between 50GB and 100GB is often close enough that the smaller increment is not worth the risk of running short.

30GB compared with 10GB and 100GB

Against 10GB, the case for 30GB is that it removes the need to think. A 10GB plan works well if you are on Wi-Fi almost constantly, but it requires a degree of awareness about video streaming that many people find tiresome. Our guide to whether 10GB of data is enough covers who that tier genuinely suits.

Against 100GB, the case for 30GB is cost, but the gap is narrower than it once was. Competition at the larger allowances has compressed pricing, so it is always worth checking both tiers rather than assuming the smaller one is cheaper by a meaningful margin. Our guide to whether 100GB of data is enough covers that comparison, including how 100GB often stacks up against unlimited.

If you are still deciding where you sit overall, our guide to how much mobile data you need works through the calculation from scratch.

What to look for in a 30GB plan

Price alone is a poor way to choose at this tier, because plans cluster closely together. Three things separate them in practice.

The first is whether the network applies annual mid-contract price rises. A plan that is slightly cheaper today can cost more across a two year term than a rival that holds prices flat, and our guide to SIM only mid-contract price rises sets out which networks do what.

The second is data rollover. If your usage varies month to month, a plan that carries unused data forward effectively gives you a larger allowance in the months you need it. Our guide to which networks offer SIM only data rollover covers the terms, which differ more than the headline feature suggests.

The third is contract length. If you are unsure whether 30GB is the right size, a 30-day SIM only deal lets you test the allowance for a month or two and move up or down without penalty, usually for a small premium over a twelve month plan.

FAQs

How long does 30GB of data last?

For typical mixed use with Wi-Fi at home and work, 30GB comfortably lasts a full month. For someone streaming video daily on mobile data, it can be gone in two to three weeks.

Is 30GB enough for Netflix or YouTube?

It is enough for occasional viewing but not for daily streaming. 30GB covers roughly ten hours of high definition video, so around twenty minutes a day, before anything else is accounted for. Lowering the quality setting in the app roughly triples what the allowance covers.

Is 30GB enough for tethering a laptop?

Only for light or occasional use. Desktop websites, cloud sync, and software updates consume far more than phone use does, and a single operating system update can take several gigabytes. If you tether regularly, size for the laptop and look at 100GB instead.

Can I use all 30GB abroad?

This depends on the network. Most that include EU roaming apply a fair usage cap that is lower than the full UK allowance, so part of your 30GB may not be usable abroad. Check the specific cap on the plan before travelling.

Conclusion

30GB is the allowance most people should default to. It is large enough to stop you monitoring your usage, small enough to avoid the premium that unlimited plans carry, and it sits in the most competitive part of the market, so the pricing is keen.

Step down to 10GB only if you are genuinely on Wi-Fi almost constantly. Step up to 100GB if you commute without Wi-Fi, tether a laptop regularly, or rely on your phone as your main connection. And whichever tier you land on, check how the network handles annual price rises before committing to a long contract.

How to choose a 30GB SIM only deal

1. Confirm 30GB is your tier. Check three months of usage in your network app and add a buffer of 20 to 30 per cent.
2. Compare on total cost, not monthly price. Factor in whether the network applies annual increases across the length of the contract.
3. Check the extras that matter to you. Rollover, roaming caps, and tethering terms differ between plans priced within pennies of each other.
4. Keep your number when you switch. Request a PAC from your current provider and give it to the new network. Our guide to keeping your number when switching to SIM only covers the process.

Editorial policy

This guide is produced by SIM Only Finder to help consumers compare mid-range data allowances across UK networks. Network terms, pricing, and plan availability are checked regularly and updated to reflect current offers. Always confirm current terms directly with the network before signing up.