Quick answer: Yes. Ofcom’s persistent misuse policy is technology-neutral: silent and abandoned calls are misuse whenever the caller controls the cause, AI or not. The 3% abandoned call rate is not a safe harbour; Ofcom’s 2016 statement says it never was. The two-second limit covers a message, not a live agent, and “live agent” is undefined.
Do Ofcom’s silent and abandoned call rules apply to AI voice agents?
They apply whatever technology placed the call. Section 128(5) of the Communications Act 2003 has two limbs: a person misuses a network or service if “(a) the effect or likely effect of his use of the network or service is to cause another person unnecessarily to suffer annoyance, inconvenience or anxiety; or (b) he uses the network or service to engage in conduct the effect or likely effect of which is to cause another person unnecessarily to suffer annoyance, inconvenience or anxiety.” Under section 128(6), the cases treated as persistent misuse include any where repetition makes clear it represents “(a) a pattern of behaviour or practice; or (b) recklessness as to whether persons suffer annoyance, inconvenience or anxiety.” The cap in section 130(4) is £2,000,000.
Under section 131, the policy in force is Ofcom’s Persistent Misuse statement, published 20 December 2016, which “applies from 1 March 2017”. It never mentions AI. Its test is causation: “Ofcom considers silent calls to be misuse wherever they are caused by something within the calling party’s responsibility or control” (A1.8), with a footnote adding “Including but not necessarily by any calling technology it uses.” An AI voice agent is a calling technology.
Responsibility runs up the chain, too. Paragraph 1.19: “The organisation engaging the third party to make the calls may be the subject of an investigation and action under the Act for persistent misuse by its representatives.” Your AI calling vendor’s silent calls are yours.
Consent and TPS screening are a separate ICO question under PECR, covered in our guide to whether AI cold calling is legal in the UK under PECR. One call can breach both regimes (A1.25–A1.26).
Silent call vs abandoned call: Ofcom’s two definitions, word for word
“Calls may either be silent or abandoned, but not both” (A1.12). The dividing line is whether the person hears a message aimed at them.
A silent call has five limbs. Paragraph A1.3 says a recipient has received a ‘silent call’ when they experience one of the following:
- “they hear nothing on answering the phone;”
- “they are disconnected by the calling party as soon as or shortly after they pick up the phone;”
- “they hear background or distant noise, whether spoken or otherwise, such as chatter (but the conversation is not directed at the call recipient), breathing or electronic beeps;”
- “they hear something else which falls short of a message (whether spoken or otherwise) directed at the call recipient; or”
- “they experience a combination of the above, such as a short period of silence followed by disconnection by the calling party (known as a ‘short duration call’).”
Limbs 2 and 4 matter most for AI agents. Ofcom names the AMD case directly: AMD “may generate silent calls by mistaking a call recipient for an answer machine and disconnecting the call” (A1.6). A beep or a half-rendered syllable before the greeting is plausibly “something else which falls short of a message”.
An abandoned call (A1.9) occurs “when a party makes a call with a view to the recipient speaking to a live agent but, instead of being connected to an agent or experiencing a silent call, the caller plays the recipient a message (usually an information message), or would do but for the call recipient disconnecting the call themselves.” A1.10 gives three examples: too few agents for live calls; an IVM caller who asks for an agent and gets an information message; and a recipient who hangs up before that message plays.
Silent calls are the worse of the two: “an even more harmful type” (A1.13), and “Action against those making silent calls is likely to be our highest priority” (A2.3). An AMD hang-up on a real person is the worst outcome an AI dialling setup can produce.
Is the 3% abandoned call rate still a safe harbour?
No. The 3% figure comes from Ofcom’s 2010 statement on tackling abandoned and silent calls (1 October 2010), Annex 1, A1.30: “The abandoned call rate shall be no more than three per cent of live calls per campaign (i.e. across call centres) or per call centre (i.e. across campaigns) over a 24 hour period.”
The 2016 statement replaced that policy and rejected the safe-harbour reading in Annex 4, A4.20: “The view held by respondents that the 3% abandoned call rate set out in the 2010 policy created a safe harbour is incorrect. Rather, it reflected a criterion for prioritising cases for action.” A4.27 goes further: “We have not included as a prioritisation criterion in the revised policy a reference to a specific abandoned call rate.” Its footnote, in full: “Whether three per cent or a different rate.”
The current policy has no number. Ofcom still calculates a rate (Annex 3), and a higher one means “Ofcom may be more likely to take action” (A3.2), but “we may take action in any case where a calling organisation makes them” (A3.1). Why do secondary pages disagree? Ofcom also publishes an edited copy of the 2016 statement without Annex 4, and “three per cent”, “3%” and “safe harbour” appear in it zero times. In the full statement they appear 6, 2 and 4 times, all in Annex 4.
| Rule | 2010 statement (superseded 1 March 2017) | 2016 statement (in force) |
|---|---|---|
| Abandoned call rate | “shall be no more than three per cent of live calls” per campaign or per call centre, per 24 hours (A1.30) | No rate. Calculated per calendar day and used for prioritising cases. The 3% “safe harbour” reading is “incorrect” (A4.20) |
| AMD false positives (a real person hung up on) | Counted in the abandoned call rate as a “reasoned estimate” (A1.18) | Silent calls, Ofcom’s “highest priority” (A1.6, A2.3), and left out of the rate (A3.5) |
| Two seconds | Information message “must start playing no later than two seconds after the telephone has been picked up”, or two seconds after the person begins to speak (A1.51) | Ofcom “may … consider” whether the recipient is connected to a message “as quickly as possible, and no longer than two seconds”. Treated as a possible aggravating factor (A2.18–A2.19) |
| Repeat calls within 72 hours | After an abandoned call, repeats “may only be made with the guaranteed presence of a live operator” (A1.54) | Repeat misuse within 72 hours without a guaranteed live agent is “likely” to be an aggravating factor (A2.9) |
| Repeat after an AMD answer-machine call | Repeats within the same 24 hours need a guaranteed live operator (A1.55) | No separate 24-hour AMD rule. An AMD false positive is a silent call, so the 72-hour factor applies |
| Ring time before hanging up | “must ring for a minimum of 15 seconds” (A1.53) | Under 15 seconds, or “left ringing for extended periods”, is “likely to cause more harm” and “likely to be subject to enforcement action” (A2.15) |
| Records | “a minimum of six months” (A1.59) | “at least six months” (A2.23) |
| Who must be available | “live operator”, meaning “a call centre agent” (A1.22) | “live agent” or “live agents”, used 17 times and never defined |
How Ofcom calculates the abandoned call rate
A3.4’s formula is abandoned calls (x) ÷ (abandoned calls (x) + live calls (y)) × 100%, “for each calendar day”. A3.3 defines a calendar day as “between midnight and midnight on a calendar day”, a campaign as “the making of calls for a single proposition to a single target audience”, and a live call as one “answered by a live individual and the call is connected to a live agent”.
A3.5 excludes silent calls, unconnected calls and answer-machine calls. Ofcom’s worked example (A3.8–A3.12) takes 1,000 calls in a day: 392 live, 8 abandoned, 200 unconnected and 400 answer machines passed to agents. The machine share is 400 ÷ (392 + 400) = 50.5%, so 8 × 50.5% = 4.04 abandoned calls are assumed to be machines, leaving 3.96. The rate is 3.96 ÷ (3.96 + 392) = 1.00%. We re-ran every step.
A low rate can hide your worst calls. Silent calls are excluded, so a campaign whose AMD hangs up on hundreds of people can report a rate near zero. Track the two numbers separately.
The two-second rule is about a message, not a live agent
A common reading, that the person must be connected to a live agent within two seconds, is not what Ofcom’s current text says. A2.18: “We also consider the length of time taken to connect the call recipient to a message has the potential to aggravate some forms of misuse.” A2.19 says Ofcom “may therefore consider in such cases whether the recipient is connected to a message as quickly as possible, and no longer than two seconds, after:”
- “where the message playing is dependent on the technology recognising a voice or sounds to classify the call, the person called begins to speak; or”
- “in any other case, the phone has been picked up.”
The footnote to “a message” reads: “Whether an information message, an automated message or an interactive message.” That puts an AI agent’s opening line within reach of the clock, starting at pickup, or at the person’s first word if your agent listens before speaking. The US rule is framed around a sales representative instead, as our comparison of AI phone agents and predictive diallers sets out.
What an Ofcom information message has to say
When a call is abandoned, Ofcom expects a recorded message, and A2.17 says what it “should” contain, in four limbs:
- “identify the party on whose behalf the call was made;”
- “explain that the party attempted to contact the recipient;”
- “provide details of a basic rate number (see above) which the recipient can call so they decline further calls from the calling party; and”
- “not include any marketing content.”
A good message does not cure the call (A2.16): “Doing so does not mean the call causes no unnecessary harm and does not prevent persistent misuse occurring.” An AI agent that falls back to a message is making an abandoned call; the message only stops it being silent.
CLI, ring time, 72 hours and six months: the other Ofcom factors
CLI. A1.20 lists four misuses, introduced with “include”, so the list is not closed (A1.21–A1.23 add misleading use of multiple CLIs): “the withholding of CLIs by those making marketing calls, in breach of the Privacy and Electronic Communications (EC Directive) Regulations 2003”; “displaying a CLI which is not authentic or valid”; “displaying a CLI which is unreturnable such that, when called, the number does not connect to an agent or an automated message”; and “displaying a CLI which is a controlled premium rate service number.” A1.24 adds three for return calls: no information about who called, no opt-out opportunity, or “the call is used as an opportunity to market to that person, without their consent.” Ofcom will “usually” treat a withheld CLI as aggravating any misuse, “particularly so in relation to silent calls” (A2.13).
Ring time. Calls “allowed to ring for less than 15 seconds before being terminated (unless answered before then) by the calling party, or are left ringing for extended periods, are likely to cause more harm and are likely to be subject to enforcement action” (A2.15).
72 hours. A2.9: Ofcom may assess “whether any calls constituting misuse are made within the 72 hours following the first instance of misuse” and “whether the calling party guaranteed the availability of a live agent for the repeat call. If not, Ofcom is likely to regard the repeated call(s) as an aggravating factor.” Not a ban, and it follows any misuse, not only an AMD false positive.
Records. Keep them “for at least six months” (A2.23), including “evidence of the accuracy of AMD” (A2.24). Ofcom is likely to look at “a six to 12-week period” when judging persistence (1.15).
Is an AI agent answering within two seconds a “live agent”?
Ofcom’s published policy does not say. The 2016 statement uses “live agent” or “live agents” 17 times and never defines either. We searched the saved text for “artificial”, “intelligence”, “AI” as a whole word, “machine learning”, “chatbot” and “live operator”. The only hits were “artificial inflation of call traffic” and “artificially to generate return calls”, neither about the caller’s technology. As a positive control on the same file, “live agent” returned 17 matches and “two seconds” returned 1. The fetch worked; the text is silent on AI.
The surrounding text leans one way. The 2010 statement’s guaranteed live operator meant a consumer “will be connected to a call centre agent” (A1.22). The 2016 statement describes IVM as including “prompts for the call recipient to either press a button or speak a response”, after which “the automated system may play some information, route the recipient to another prompt or connect them with a human operator” (footnote 15). Nothing in the text says a more capable machine changes category.
The defensive reading: assume an AI agent is not a live agent, and design campaigns that pass either way. PECR raises the same question about “live speech”, set out in the Live-Speech Test on our PECR page.
The first-word test: where each AI-agent behaviour lands under Ofcom’s policy
Ofcom’s categories turn on what a person hears after answering. We call this the first-word test: find the first sound your system plays after pickup, then look up the paragraph it triggers.
| What happens after the person answers | Ofcom category | Paragraph | Treatment |
|---|---|---|---|
| AI greets within 2 seconds of pickup (or of the person starting to speak) and names the caller | Neither silent nor abandoned on the text. Whether it is a “live call” is unresolved | A1.3, A1.9, A3.3 | No silent or abandoned category triggered. Keep the recording and timestamp |
| AI greeting starts more than 2 seconds after pickup | Not silent if a message follows. The delay can aggravate misuse | A2.18–A2.19 | Aggravating factor in a misuse case |
| Person hears a beep, tone or fragment, then the line drops | Silent call | A1.3 limbs 3–5 | Highest enforcement priority |
| AMD or the agent classifies a person as voicemail and hangs up | Silent call | A1.3 limb 2, A1.6 | Highest priority. Left out of the abandoned call rate |
| Dialler dials past agent capacity; the person hears silence | Silent call | A1.3 limb 1, A1.5 | Highest priority |
| Dialler dials past agent capacity; the person hears a recorded message | Abandoned call | A1.9, A1.14 | Misuse. Message content judged against A2.17 |
| Person asks for a human; none is free; message plays | Abandoned call (IVM example) | A1.10 limb 2 | Misuse. Message content judged against A2.17 |
| Person asks for a human and is kept waiting | Possible misuse | A1.28–A1.32 | “unfairly long wait-time” judged case by case. No marketing content while waiting unless the requirements are met |
| Dead air mid-conversation (a tool call or lookup) | Not addressed. The call has already carried a message directed at the recipient | None (compare A1.12) | No Ofcom threshold. Treat as a customer-experience defect |
| Unanswered call cut before 15 seconds | Aggravating factor | A2.15 | “likely to be subject to enforcement action” |
| Repeat call within 72 hours of a misuse call, without a guaranteed live agent | Aggravating factor | A2.9 | “likely” aggravating |
| CLI withheld on marketing calls in breach of PECR, or CLI that is invalid, unreturnable or premium rate | Misuse of a CLI facility | A1.20, A2.12–A2.13 | Serious. Can be a priority for enforcement |
On the dead-air row: the five silent-call limbs describe calls where no message directed at the recipient is delivered, and A1.12 draws the silent/abandoned line at that message. Once your agent has spoken, nothing in the statement limits a later pause. It still costs you the conversation; our breakdown of why AI voice agents go silent on tool calls covers the budget.
Worked example: 20,000 dials in one calendar day, read two ways
Hypothetical inputs, to show the method. One campaign, one calendar day, 20,000 dials:
- 11,000 unconnected (excluded, A3.5)
- 5,000 answer machines detected and dropped by AMD (excluded, A3.5)
- 4,000 answered by a person. Of those, 3,900 hear the AI agent’s greeting within 2 seconds, 60 hear an information message because the agent pool was at its concurrency limit, and 40 are AMD false positives: real people classified as machines and hung up on.
Reading A: the AI agent is a live agent. x = 60 and y = 3,900. The rate is 60 ÷ (60 + 3,900) = 1.52%. The 40 AMD false positives are silent calls and stay out of the rate under A3.5, so a report of “1.52%” is correct and still hides 40 of the calls Ofcom calls its highest priority.
Reading B (defensive): only a human is a live agent. Say 300 conversations ask for, or are escalated to, a human, and 45 hear “no one is available” (A1.10 limb 2). The 255 who reached a person are the live calls. We also count the 60 capacity messages as abandoned, our conservative choice. x = 105 and y = 255, so the rate is 105 ÷ (105 + 255) = 29.17%.
The other 3,600 AI-only conversations sit in neither numerator nor denominator. The same day reads 1.52% or 29.17% depending on a definition Ofcom’s published policy does not give. Design to Reading B, and log the 40 silent calls under either.
What to set up before your first UK AI calling campaign
- Measure time to first word. Log pickup (or start of speech) and the greeting’s first audio frame on every call; report the share over 2 seconds per campaign per calendar day.
- Count AMD false positives as silent calls. Sample machine-classified calls and label them by ear. Our guide to answering machine detection settings by cost shows how to price a false-machine error; under Ofcom’s policy, price it high.
- Cap dialling at agent capacity. A2.21 lists “set the dialling rate of any ACS at a rate appropriate to the number of call agents employed”. For AI, that means concurrency, not headcount.
- Write the information message to A2.17’s four limbs and test the pool-full path.
- Staff the handoff. Track waits and “no one available” outcomes.
- Present a returnable, basic-rate CLI whose answerer identifies you and offers an opt-out.
- Enforce a 72-hour suppression on any number that got a silent or abandoned call, unless a human is guaranteed on the repeat.
- Keep call records for at least six months, including AMD accuracy evidence.
Volume is why this bites harder for AI calling. Zian reports a 2,736% increase in lead contact rates, and its SmartReach AI™ layer sets follow-up timing and pacing. Every extra answered call is another chance at a 72-hour repeat or a silent call, so those connections only help if each one passes the first-word test.
When this is a question for a lawyer, Ofcom or the ICO
This page reads Ofcom’s published policy and the Act; it is not legal advice, and the policy does not bind Ofcom’s discretion (1.2, footnote 4). Take advice before launch if your volume is large, if your design depends on Reading A, or if you receive an information request under section 135.
Frequently asked questions
Is the 3% abandoned call rate still allowed in the UK?
There is no allowed rate. Ofcom’s 2016 persistent misuse statement, in force since 1 March 2017, calls the view that 3% was a safe harbour “incorrect” at paragraph A4.20 of the statement, and it removed any specific rate from its prioritisation criteria.
Does an AI voice agent count as a live agent for Ofcom?
Ofcom’s published policy does not say. The 2016 statement uses the phrase live agent (or live agents) 17 times without defining it and does not mention AI. Its description of automated interactive systems contrasts them with a human operator, so the safer course is to assume an AI agent is not a live agent.
What is Ofcom’s two-second rule?
Ofcom may consider whether the person is connected to a message as quickly as possible and no later than two seconds after they begin to speak, where the system recognises a voice or sounds to classify the call, or otherwise after pickup. It is an aggravating factor in a misuse case, and it concerns a message, not a live agent.
Is an answering machine detection hang-up on a real person a silent call?
Yes. Ofcom says AMD may generate silent calls by mistaking a call recipient for an answer machine and disconnecting the call. Silent calls are Ofcom’s highest enforcement priority and are left out of the abandoned call rate, so a low rate does not mean none happened.
How much can Ofcom fine for silent and abandoned calls?
Up to £2,000,000. The cap is set in section 130(4) of the Communications Act 2003, and the amount must be appropriate and proportionate to the misuse.
Do I need to wait 72 hours before calling a number again?
Only after a call that was itself misuse, such as a silent or abandoned call, and even then it is not a ban. Ofcom is likely to treat a repeat misuse call within 72 hours as aggravating unless a live agent was guaranteed for the repeat.
Where every figure on this page comes from
| Figure | Who published it | Link | Date read |
|---|---|---|---|
| £2,000,000 maximum penalty | UK Parliament, Communications Act 2003 s130(4) | legislation.gov.uk s130 | 26 September 2026 |
| s128(5) two limbs, s128(6) two limbs | UK Parliament, Communications Act 2003 s128 | legislation.gov.uk s128 | 26 September 2026 |
| 20 December 2016 publication, applies from 1 March 2017 | Ofcom, Persistent Misuse statement | Ofcom statement page | 26 September 2026 (Internet Archive capture of 21 July 2025) |
| 3% “safe harbour” reading “incorrect”; no specific rate | Ofcom, 2016 statement, A4.20 and A4.27 fn 53 | Ofcom statement PDF | 26 September 2026 (Internet Archive capture of 17 August 2026) |
| Five silent-call limbs; three abandoned-call examples | Ofcom, 2016 statement, A1.3 and A1.10 | As above | 26 September 2026 |
| Two seconds (message timing) | Ofcom, 2016 statement, A2.19 | As above | 26 September 2026 |
| 15 seconds ring time | Ofcom, 2016 statement, A2.15 | As above | 26 September 2026 |
| 72 hours repeat factor | Ofcom, 2016 statement, A2.9 | As above | 26 September 2026 |
| Six months of records | Ofcom, 2016 statement, A2.23 | As above | 26 September 2026 |
| Six to 12-week assessment period | Ofcom, 2016 statement, 1.15 | As above | 26 September 2026 |
| 1,000 / 392 / 8 / 200 / 400 calls; 50.5%; 4.04; 3.96; 1.00% | Ofcom, 2016 statement, A3.8–A3.12 | As above | 26 September 2026 |
| “live agent(s)” 17 matches; AI terms 0 relevant matches; “three per cent” 6, “3%” 2, “safe harbour” 4 (all in Annex 4; 0 in the edited version) | Zian count of Ofcom’s 2016 statement text | As above | 26 September 2026 |
| 3% per 24 hours; 2 seconds; 15 seconds; 72 hours; six months (2010 rules) | Ofcom, Tackling abandoned and silent calls statement, 1 October 2010, Annex 1 | Ofcom 2010 statement page | 26 September 2026 (capture of 6 June 2023) |
| 20,000 dials and all worked-example inputs; 1.52%; 29.17% | Zian, hypothetical inputs for illustration | This page | 26 September 2026 |
| 2,736% increase in lead contact rates | Zian (first-party figure) | zian.ai homepage | 26 September 2026 |
A note on access: ofcom.org.uk served a bot-verification challenge to every request from our server on 26 September 2026, so Ofcom’s text was read from Internet Archive copies of Ofcom’s own files, on the capture dates shown. Ofcom revised the statement file on 20 January 2026, and that revision is what the statement’s URL served when captured on 17 August 2026. The only change from the 2016 text is one added sentence at the end of A1.10: “Please see our Refresher messaging on Silent and Abandoned Calls for more information.” Every quotation on this page is identical in both versions. Ofcom’s refresher page itself (dated 22 January 2026 in search results) was behind the same challenge and has no Internet Archive copy, so we have not read it and nothing on this page relies on it. The edited version of the statement (captured 15 February 2026) differs from the full statement only by omitting Annex 4.
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