Is Unlimited Data Really Unlimited?

What is a fair usage policy?

A fair usage policy (FUP) sets a threshold for what a network considers reasonable monthly data consumption. If you exceed that threshold, the network may reduce your connection speeds for the rest of the billing period. Your data does not stop working, but it may become noticeably slower.

Fair usage policies are permitted under Ofcom rules, provided they are clearly stated in a network's terms and conditions and are reasonable in their application. They are primarily aimed at preventing a small number of users from consuming extremely large volumes of data in ways that affect network performance for everyone else. For the vast majority of users, fair usage thresholds are high enough that they will never come close to triggering them.

Which networks have fair usage policies on unlimited data?

The following networks apply a fair usage threshold on their unlimited data plans. Always check the current terms on the network's website before signing up as these figures can change:

• EE: 600GB per month. Exceeding this twice within six months may result in speed restrictions or a transfer to a different plan.
• Giffgaff: 650GB per month. Exceeding this twice within six months may result in speed restrictions or additional charges.
• Honest Mobile: speeds reduced to 3G if you use over 650GB in a billing cycle.
• O2: 650GB per month. Exceeding this twice within six months may result in speed restrictions or a transfer to a different plan.
• Tesco Mobile: no specific data cap stated, but excessive use that affects other customers may result in a warning, speed restrictions, or suspension.
• Lycamobile: 450GB per month. Exceeding this twice within six months may result in speed restrictions.
• Vodafone: 600GB per month. Exceeding this twice within six months may result in investigation and possible transfer to a different plan.

For networks running on the VodafoneThree network (including Smarty, iD Mobile, Talkmobile, Voxi, and Asda Mobile), post-merger terms are still being updated. Check the current terms with each network directly before signing up.

The following networks do not currently state a specific fair usage threshold on their unlimited data plans:

• Asda Mobile
• iD Mobile
• Lebara
• Sky Mobile
• Smarty
• Talkmobile
• Three: no stated fair usage policy on unlimited data plans. Three continues to sell plans under its own brand following the completion of its merger with Vodafone in June 2025.
• Voxi

Note that even networks without a stated threshold reserve the right to take action against usage they consider abusive or that negatively affects the network for other customers.

What counts as excessive data usage?

Fair usage policies are generally aimed at preventing a small minority of users from using a mobile unlimited plan as a home broadband substitute or running data-intensive servers. Streaming video, browsing, video calls, social media, and general everyday smartphone use will not come close to triggering fair usage thresholds on any UK network. The thresholds are set at hundreds of gigabytes per month precisely because they are not meant to affect normal usage.

Does unlimited data include roaming?

No. Unlimited data plans cover your domestic UK usage. When you travel abroad, your data usage is subject to separate roaming allowances and fair use limits, which are set independently from your UK plan.

Most UK networks include EU roaming on their plans, but cap the amount of data you can use abroad each month. This cap is separate from your domestic unlimited allowance. For example, a network might include 12GB of roaming data in the EU even if your domestic plan is unlimited. Check the specific terms of the plan you are considering before travelling. For more detail on how roaming works, see our guide to EU roaming fees.

Do I need unlimited data?

According to Ofcom's Connected Nations report, the average UK mobile user consumes around 10.6GB of data per month. If your usage is around this level or below, an unlimited plan is unlikely to represent the best value. A capped plan at a lower monthly cost will often work out cheaper overall.

Unlimited data makes sense if you regularly stream video on mobile, use your phone as a hotspot for other devices, or work remotely without consistent Wi-Fi access. You can compare current unlimited data SIM-only deals on our deals page, where results are sorted by monthly cost.

FAQs

Will my data actually stop if I exceed the fair usage limit?

No. Exceeding a fair usage threshold typically results in reduced speeds for the remainder of your billing period, not a complete cut-off. Your data continues to work, but may feel noticeably slower for heavy tasks like video streaming.

Are fair usage limits applied automatically?

Yes. Speed reductions are applied automatically by the network once the threshold is crossed. You do not usually receive a warning in advance, though your network may contact you if you exceed the limit repeatedly.

Where can I compare unlimited data deals?

You can compare all current unlimited data SIM-only deals on our deals page, sorted by monthly cost and filterable by network.