Are power diallers legal in the UK?

Yes. No UK law bans power diallers, or predictive or parallel ones. What the law cares about is what a dialler does to the person who answers.

I build a dialler, and this page sets out what the law and Ofcom say, and where the sales pages disagree with each other.

What's actually regulated

Ofcom's powers come from sections 128 and 130 of the Communications Act 2003, which deals with "persistent misuse" of a phone network. The test is about effect: using a network or service in a way that causes, or is likely to cause, someone "unnecessarily to suffer annoyance, inconvenience or anxiety", often enough to show a pattern of behaviour.

Ofcom's policy on how it uses that power, published in 2016, is framed around harm rather than equipment. In its words: "Where evidence shows behaviour is harmful and falls within the statutory definition, it is unlawful." Its examples are silent and abandoned calls, whatever causes them, including no technology at all. An agent who hangs up the moment someone answers is making a silent call too.

Ofcom's January 2026 refresher names diallers directly. It says organisations should ensure "Automated Calling Systems (ACS), dialler systems and call handling arrangements do not generate these types of calls." It doesn't ban any of them.

So the question isn't "is my dialler legal?" It's "does my dialler cause silent or abandoned calls?"

Why "power dialler" tells you very little

The trouble with the question in the title is that the industry doesn't agree what a power dialler is.

These are vendor definitions, not legal ones. No UK statute or Ofcom document defines a power dialler. Kixie itself says the term "is used inconsistently".

That matters, because one line at a time and four lines at a time carry very different risks for UK callers.

What gets diallers into trouble

Dropping people who answer

If a dialler rings several numbers for one rep and two people answer, one of them can get dropped. Ofcom's description of a silent call includes being "disconnected by the calling party as soon as or shortly after they pick up the phone." On my reading of that, a person cut off because someone else answered first has had a silent call, whatever the dialler is called.

The vendors disagree about how big this risk is. Kixie says parallel dialling eliminates abandoned calls. CloudTalk, which sells a parallel dialler, says "Every extra line raises the chance that two people answer at once and one of them gets dropped".

Answer machine detection

Answer machine detection (AMD) tries to tell a person from a voicemail. Ofcom says it "may generate silent calls by mistaking a call recipient for an answer machine and disconnecting the call." That can happen on a one-line dialler too. So "one line at a time" isn't a guarantee on its own.

Overdialling

Ofcom says silent calls can happen when an automated system has "over-dialled", so every agent is busy when someone answers. One of the things it looks at is whether the dialling rate was set "at a rate appropriate to the number of call agents employed".

For more on how each dialler type behaves, and how Ofcom calculates an abandoned call rate, see progressive, power, parallel and predictive diallers under Ofcom's rules.

Live calls versus automated calls

The other rule people mix up is PECR regulation 19. It bans recorded marketing messages sent through an automated calling system unless the subscriber has consented to them in advance. The ICO is clear that "General consent for marketing, or even consent for live calls, is not enough".

Regulation 19 is about recorded marketing messages. On my reading of it, a dialler that connects an answered call to a real person is making live calls, which the ICO describes as "a telephone call where a live person is speaking to the person they are calling." Those fall under the live call rules: TPS and CTPS screening, caller ID, giving your name, honouring objections.

One case shows where the line can move. In 2025 the ICO fined energy firms after calls in which "scripted lines recorded by voice actors" were "played by call agents abroad". The ICO treated them as automated calls under regulation 19, even though call agents were playing the lines through avatar software. If you're looking at AI voice tools for calling, that case is worth reading first.

Choosing a dialler for UK calling

The safer set-up is one designed not to generate silent or abandoned calls. To me that means a rep is on the line before the call connects, one call at a time, with no answer machine detection hanging up on people. That lowers the risk rather than removing it. A rep who hangs up when someone answers is still making a silent call.

That's how I built KIK Studio. It's progressive only. The rep places each call or the next one starts after they save an outcome, one call at a time, and a ringing call can't be ended by the rep before 15 seconds. It's slower than a parallel dialler. For UK calling, I think that's the right trade.

Whatever you use, the rest of the calling rules still apply. They're all in the UK cold calling law guide.