O2 Spend Cap Explained: Set a Limit on Your Mobile Bill

O2’s Spend Cap is a free tool that lets Pay Monthly customers set a ceiling on charges that fall outside their monthly plan. Since October 2018, Ofcom has required all UK mobile networks to offer this option. The cap works as a safety net: once you hit your chosen limit, most chargeable services are blocked until your next billing cycle starts.

You’ll receive a text alert at 50% and again at 100% of your cap. This gives you time to adjust your usage or top up your allowance before services are restricted.

Which charges does the cap control?

The Spend Cap applies only to services used beyond your monthly allowance. If you pay £30 per month and set a £10 cap, your maximum bill would be £40 before extra services are cut off.

Charges included:

• Calls, texts, and data after your allowance runs out
• Premium rate and non-geographical numbers
• International calls and texts made from the UK
• Roaming usage outside O2’s Europe Zone
• Directory enquiry services

Charges not included:

Some costs sit outside the cap and will still appear on your bill. Your recurring Airtime and Device Plan payments are always charged in full. Insurance premiums, Bolt On purchases, and charity donations made via your phone are also excluded. “Charge to Mobile” services (used to buy apps or digital content) bypass the cap entirely. Account fees for paper bills or late payments are not covered either.

Setting your cap: a quick walkthrough

You can add or adjust your Spend Cap at no cost through My O2.

Choosing the right cap level

O2 offers several cap amounts: £0, £5, £10, £15, £20, £30, £60, £100, and £200. The right choice depends on your usage patterns.

A £0 cap is the strictest. It blocks all out-of-bundle spending, so your bill will never exceed your monthly plan cost. This suits anyone who wants absolute certainty and rarely needs extra services.

Caps between £5 and £30 provide a small cushion. If you occasionally make an international call or slightly overshoot your data, a modest cap prevents bill shock without locking you out entirely.

Higher caps (£60 to £200) are designed for users who regularly go beyond their allowance but still want a hard limit. Once you hit 100% of any cap, O2 bars further chargeable usage. You can still dial 999 and O2 customer service.

Spend Caps for business accounts

O2 Business customers can also apply Spend Caps to control costs across their account. The bill payer or an authorised user sets caps for individual lines through the My O2 Business portal.

Business accounts have access to £0, £5, £10, £15, £20, £30, £50, £75, £100, and £200 caps. The same list of included and excluded charges applies. Note that Spend Caps are incompatible with shared data tariffs and Mobile Device Management systems.