O2 Now Uses AI to Block 3 Million Scam Calls a Week in the UK

O2 has switched on AI-powered fraud call blocking for all of its UK customers, and the numbers behind the move are striking. The network says the system is now expected to block more than 3 million malicious calls every week before they ever reach a phone. The service is free, it is switched on automatically, and customers do not need to download anything or change a setting to benefit.

The announcement, made on Friday 30 October 2026, follows a trial earlier in the autumn. O2 says it is the first UK mobile operator to block all calls suspected of being scams in this way, rather than simply warning customers about them. For anyone who has been woken by a fake bank call or tricked by a number that looked local, that difference matters. A warning still leaves the decision with you, in the few seconds before you answer. Blocking takes the call away entirely.

What O2 has actually launched

The new system works at network level, which means it checks calls as they travel through O2’s network, before they are connected to your handset. It uses AI-assisted algorithms developed with Hiya, a company that specialises in call protection, to spot patterns linked to nuisance and fraudulent callers. Those patterns are refined over time using customer reports and fresh analysis of how scam callers behave.

O2 already blocks calls from numbers on Ofcom’s Do Not Originate list, a register of numbers that should never make outbound calls. The new layer goes further. It looks at live behaviour across the network, so a number that starts making large numbers of short calls, or that matches known scam patterns, can be stopped even if it has not been reported before. O2 says that during the trial, a fraud-labelled number tried three times as many calls after being blocked as before, which the company reads as a sign that the system is disrupting fraudsters and wasting their time.

The practical point for customers is simple. If you are on O2, the protection applies to compatible devices without any action from you. You do not pay extra, you do not need a separate app, and you do not need to remember to turn anything on. That matters because the people most at risk from phone scams are often the least likely to hunt through settings menus for a security feature.

Why scam calls are still such a problem

Phone scams work because they exploit trust and urgency. A caller claims to be from your bank, a delivery company, HMRC, or a tech support team, and then creates a reason to act now. The number on screen can look convincing, especially when fraudsters spoof a familiar area code or a number similar to one you already know. Once a victim is engaged, the conversation can move quickly to codes, passwords, or payments.

Network-level blocking attacks the economics of that model. Scam operations depend on volume. If thousands of calls never connect, the cost of running the operation rises and the return falls. It does not end phone fraud on its own, and O2 does not claim that it does, but it removes a large share of the attempts before a human has to judge them. That is a useful shift. Most advice about scam calls asks the potential victim to be sharper, calmer, and more suspicious in the moment. Blocking asks less of the victim and more of the network.

What this does not do

It is worth being clear about the limits. O2’s system targets calls on its own network, so it cannot stop scam calls that arrive through other channels, such as messaging apps, email, or social media. It also cannot guarantee that every scam call will be caught. Some fraudsters will adapt, change numbers, or find new routes, and some legitimate calls could in theory be caught by mistake, although O2 presents the system as focused on suspected scam traffic.

Customers should still treat unexpected calls with care. If a caller asks for a password, a one-time code, or a payment, hang up and contact the organisation directly using a number from its official website or the back of your card. Never call back a number given to you by the suspicious caller. If a call claims your account has been compromised, use a different method to check, such as your bank’s app or a number you already trust.

What to watch next

Other UK networks offer varying levels of scam protection, and O2’s claim to be first with this kind of blanket blocking will invite comparison. If the weekly figure of more than 3 million blocked calls holds up, rivals may face pressure to match it or explain why their approach differs. Regulators and consumer groups will also want to see evidence over time, not just a launch-week figure, including how many legitimate calls are affected and how quickly new scam patterns are caught.

If you are an O2 customer, there is nothing to set up. If you are on another network, it is still worth asking what scam call protection your provider offers at network level, and what handset settings you can switch on today. Scam callers rely on reaching you. Anything that stops them before they do is a step in the right direction.

Frequently Asked Questions

Do O2 customers need to do anything to get the new scam call blocking?

No. O2 says the AI-powered blocking is rolled out automatically across compatible devices and is free of charge. Customers do not need to install an app or change a setting to benefit.

How many scam calls does O2 say it will block?

O2 says more than 3 million malicious calls a week are now expected to be blocked in real time before they reach customers’ phones. The figure follows a trial earlier in the autumn of 2026.

Does this mean O2 customers will never receive a scam call again?

No. The system blocks calls suspected of being scams at network level, but no system catches everything. Customers should still be cautious with unexpected callers, never share passwords or one-time codes, and contact organisations directly through trusted numbers if a call seems suspicious.