Progressive, power, parallel and predictive diallers under Ofcom's rules.

Dialler names are marketing language. Ofcom doesn't use them in its current policy, and the vendors don't agree on what they mean. What Ofcom regulates is the outcome: silent calls, abandoned calls and other persistent misuse.

So the useful questions about any dialler are how many numbers it dials per rep, and what happens to the person who answers.

The five types, by the common definitions

These are vendor definitions, not regulatory ones. I've used the most common reading of each, and noted where vendors disagree. The risk column is my own reading, not a vendor or Ofcom rating.

Two contradictions worth knowing:

• Power. Regal says power dials one number per available agent and progressive "dials a set number per agent using AMD". Genesys and Vonage say progressive is one call per available agent.
• Parallel. CloudTalk says parallel and multi-line "are the same thing". Kixie treats a two to four line power dialler and a parallel dialler of up to ten lines as different categories.

If a vendor tells you their product is a power dialler, ask how many numbers it rings per rep. That's the answer that matters.

What Ofcom counts as harm

Ofcom's 2016 policy describes two main kinds of call it wants stopped.

Silent calls. The person hears nothing, or is "disconnected by the calling party as soon as or shortly after they pick up the phone". Ofcom says these can happen when an automated system "has 'over-dialled', so that all the call centre agents are busy when the call recipient answers". Ofcom calls tackling them its "current top priority".

Abandoned calls. The person answers, no rep is free, and a recorded message plays instead. Ofcom expects that information message within two seconds. It also says a message "does not mean the call causes no unnecessary harm and does not prevent persistent misuse occurring."

Ofcom treats silent and abandoned as separate categories: "Calls may either be silent or abandoned, but not both." And it says plainly: "Calling parties should not make silent or abandoned calls."

How the abandoned call rate is calculated

Ofcom measures an abandoned call rate per calendar day, per campaign or per call centre:

Abandoned call rate = abandoned calls ÷ (abandoned calls + live calls) × 100%

Live calls are those "answered by a live individual" and "connected to a live agent". Left out of the calculation entirely: silent calls, unconnected calls, and calls to answer machines.

Ofcom's worked example uses 1,000 dials. It comes out at 1.00%, because only the calls where a person was reached count. Unanswered numbers and answer machines don't.

Two things follow from that formula.

1. The rate leaves out silent calls. A dialler can report a low abandoned call rate while producing silent calls, for example when answer machine detection mistakes a person for a machine and hangs up. Those are the calls Ofcom says are its top priority.
2. No rate is a permission slip. Ofcom uses the rate as one factor in deciding whether to act, and said in 2016 that the old 3% figure was never a safe harbour. More on that in the UK cold calling law guide.

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."

If Ofcom investigates, it is likely to ask for "information about the type of ACS/AMD in use, detailed records of calls and evidence of the accuracy of AMD."

Ofcom's penalties under its silent and abandoned calls programme

Ofcom ran an enforcement programme on silent and abandoned calls from 2006 to January 2023. Some of the penalties on its published record:

Ofcom's own tally in 2016 was eight penalties, ranging from £8,000 to £750,000, under its earlier policy. The maximum Ofcom can impose has been £2 million since 2010.

When it closed the programme in January 2023, Ofcom said complaints had fallen to 15,186, from 42,822 in 2016. Its 2026 refresher says closing the programme doesn't stop it acting if it finds this kind of misuse.

What Ofcom looks at in a dialler set-up

Among the factors in Ofcom's 2016 policy:

• whether the dialling rate was set "at a rate appropriate to the number of call agents employed"
• whether systems are tested "when they are set up or changed"
• whether dialling technology "is managed by competent persons"
• whether further calls constituting misuse were made within 72 hours of the first one
• whether a valid, returnable caller ID was shown, and whether many different numbers were used to mislead

Where KIK Studio sits

KIK Studio is progressive only. The rep places each call or the next one starts after they've saved an outcome, one call at a time, so a rep is on the line before anyone answers. There's no answer machine detection hanging up on people, and a ringing call can't be ended by the rep before 15 seconds.

That's slower than a parallel or predictive dialler. For UK B2B calling I think that's the right trade, because it avoids the main ways diallers create silent and abandoned calls: overdialling, several lines per rep and answer machine detection. It doesn't make silent calls impossible. A rep who hangs up when someone answers is still making one.

For the short answer on legality, see are power diallers legal in the UK?