TL;DR
- Silent calls are usually abandoned calls from predictive diallers — automated systems that dial more numbers than agents are available to handle.
- Ofcom requires organisations using predictive diallers to keep their abandoned-call rate below 3% of live calls per campaign per day.
- When a call is abandoned, the organisation must play an information message; simply going silent is a breach of Ofcom's rules.
- You can report silent calls to Ofcom via its online tool; Ofcom can investigate and direct operators to take action against persistent misuse.
- Not all silent calls come from diallers — some may indicate line-testing, spoofing, or 'wangiri'-style fraud; treat unfamiliar missed calls with caution.
Why silent calls happen
The majority of silent calls reaching UK consumers originate from predictive diallers used by call centres. A predictive dialler is software that automatically dials multiple telephone numbers simultaneously, connecting answered calls to available agents. Because the software predicts how long each conversation will last, it dials ahead to keep agents continuously occupied. When more calls are answered than agents are free to take, the surplus calls are “abandoned” — the line connects, but no agent is available, and the caller either plays a message or simply disconnects. The recipient hears a brief silence, or sometimes a click, followed by either a short recorded announcement or nothing at all.
High-volume outbound calling organisations — including claims management companies, financial services firms, utilities, and market research companies — use predictive diallers because they significantly increase the proportion of time agents spend in conversation rather than waiting. The efficiency gain for call centres comes at the cost of an experience that can be alarming or frustrating for the person receiving the call, particularly if it happens repeatedly from varying numbers.
Ofcom's rules on abandoned and silent calls
Ofcom's Statement on Persistent Misuse of an Electronic Communications Network or Service sets out specific obligations for organisations using predictive diallers or other automated calling technology. The rules require that the abandoned-call rate must not exceed three per cent of live calls per campaign per day. Calls in excess of that threshold constitute persistent misuse under the Communications Act 2003.
When a call is abandoned — that is, a call that connected to a live person but could not be passed to an agent — the organisation must play a brief information message. That message must not include any marketing content and must provide a freephone number the recipient can call. Critically, simply disconnecting or leaving the line silent without playing the information message is itself a breach of Ofcom's rules, independently of whether the abandoned-call rate has been exceeded. Ofcom's published guidance also states that the same number should not receive an abandoned call more than once in a 72-hour period.
| Stage | What you should do | Where it goes |
|---|---|---|
| Note the details | Record the date, time, number displayed, and what you heard (silence, click, recorded message) | Supports your report to Ofcom |
| Report to Ofcom | Use the online tool at ofcom.org.uk/phones-and-broadband/phone-calls/nuisance-calls | Ofcom collates reports and can open persistent-misuse investigations |
| Forward to 7726 (SPAM) | If you received the call on a mobile, text the number to 7726 to alert your operator | Operator may flag or block the originating number network-wide |
| Register with TPS | Register at tpsonline.org.uk if not already registered | Limits unsolicited marketing calls from compliant UK organisations; does not technically block calls |
| Consider call-blocking tools | Ask your operator about spam-filtering features; consider a third-party call-blocking app | Practical supplement to regulatory reporting |
Other causes of silent calls
Not every silent call comes from a predictive dialler. A smaller proportion originate from line-testing activity carried out by telecommunications engineers or automated systems checking number validity. These are typically isolated occurrences rather than repeated contacts and are generally not a cause for concern. However, repeated silent calls at similar times of day, particularly from mobile or international numbers, may indicate a different type of activity.
One such type is “wangiri” fraud — a name derived from a Japanese term meaning “one ring and cut.” In wangiri, a caller lets your phone ring once or gives a very brief connection, hoping you will call back the displayed number, which turns out to be a premium-rate international number that charges a high per-minute fee. If you receive a short call or a voicemail left in silence from an unfamiliar international number, do not call it back; instead, look up the number online before deciding whether to return the call.
How to report silent calls
Ofcom's primary tool for receiving reports of nuisance and silent calls is its online reporting form at ofcom.org.uk. When submitting a report, provide as much detail as possible: the date and time of each call, the number that displayed (even if withheld), whether you heard anything at all on the line, and how frequently the calls have occurred. Ofcom uses aggregated complaint data to identify organisations whose call behaviour exceeds the persistent-misuse threshold.
For mobile users, forwarding the calling number to 7726 by text is a complementary action that sends intelligence directly to your mobile operator's spam-detection team. Operators can use this data to apply network-level flagging or blocking to numbers generating high complaint volumes. You can also register your number with the TPS if you have not already done so, to create a legal obligation on UK marketing callers not to contact you; this works alongside rather than instead of reporting silent calls to Ofcom.
What Ofcom can do
Ofcom's enforcement powers in relation to silent and abandoned calls flow from the persistent-misuse provisions of the Communications Act 2003. Where Ofcom investigates an organisation and finds that its calling practices amount to persistent misuse — for example, a sustained pattern of abandoned calls above the three per cent threshold, or a failure to play the required information message — Ofcom can issue a formal notification requiring the organisation to cease the misuse. It can also work with telecommunications operators to restrict the organisation's access to the UK's telephone network.
Ofcom publishes enforcement decisions and updates on its nuisance-call work, including both formal enforcement actions and its wider work with industry on technical standards designed to reduce abandoned call rates. Its annual research on nuisance calls provides data on how many consumers experience silent and abandoned calls and how those numbers have changed over time. The most recent reports and enforcement records are available on ofcom.org.uk.
What this means in practice
Sandra, a retired teacher in Cardiff, began receiving two or three silent calls a week on her mobile. Each time she answered, she heard nothing — no message, no voice — and the call disconnected after a few seconds. She noted each call in a diary, recording the date, time, and the number displayed. After a week she submitted a report to Ofcom's online tool, pasting in the numbers and the dates. She also forwarded each number to 7726 by text. After a fortnight, her operator's spam-alert system began displaying a “possible spam” warning for one of the numbers before it connected, allowing her to decline those calls automatically. The Ofcom report contributed to the regulator's running intelligence picture; a few months later, Ofcom published a persistent-misuse enforcement action referencing a batch of complaint numbers that matched the pattern Sandra had experienced.
Related Guides
How we verified this
This article was compiled using Ofcom's Statement on Persistent Misuse of an Electronic Communications Network or Service, Ofcom's published nuisance calls guidance and enforcement records at ofcom.org.uk, and the Communications Act 2003 as published on legislation.gov.uk.
Disclaimer: Kaeltripton.com is an independent UK editorial publisher. We are not regulated by Ofcom or the FCA and we do not sell or arrange mobile services, insurance, or financial products. This content is for general information only and is not legal, financial, or technical advice. Rules, prices, and operator policies change. Verify the current position with Ofcom, GOV.UK, the ICO, or your provider before acting. ICO registered ZC135439. Last reviewed: 2026-06-05.
Frequently Asked Questions
What is a silent call?
A silent call is a telephone call that connects to the recipient but has no voice or audio on the line — the recipient answers and hears silence or a faint click before the call disconnects. Most silent calls in the UK are abandoned calls generated by predictive diallers: automated calling systems that dialled more numbers than available agents could handle, leaving the connected call with no one on the other end.
Why do I keep getting silent calls?
Repeated silent calls are most commonly produced by call centres using predictive diallers that are running their abandoned-call rate above Ofcom's three per cent limit, or that are failing to play the required information message when a call is abandoned. Your number may have entered a marketing call list — through a data purchase, a website form, or a directory listing — and the organisation calling you is running high-volume outbound campaigns. Less frequently, repeated silent calls can signal wangiri fraud or spoofed-number activity.
Are silent calls illegal?
Silent abandoned calls that do not play the required Ofcom information message are a breach of Ofcom's persistent-misuse rules under the Communications Act 2003. This is a regulatory matter rather than a criminal offence in most cases. If an organisation's abandoned-call rate exceeds three per cent of live calls per campaign per day, or if it fails to play the required message, it is in breach of Ofcom's statement and can be subject to enforcement action. Scam silent calls connected to fraud may involve criminal conduct under separate legislation.
How do I report silent calls?
Report silent calls to Ofcom using the online tool at ofcom.org.uk/phones-and-broadband/phone-calls/nuisance-calls. Provide the calling number, date, time, and what you experienced. For mobile calls, also forward the number by texting 7726 to alert your operator. Register with TPS at tpsonline.org.uk if you have not already done so. Keep a log of calls with dates, times, and numbers to support any report or complaint.
What has Ofcom done about silent calls?
Ofcom has published a Statement on Persistent Misuse and issues guidance to industry on acceptable abandoned-call rates. It has carried out enforcement actions against organisations found to be operating predictive diallers in breach of its rules, requiring them to cease misuse and in some cases working with operators to restrict network access. Ofcom also publishes annual research on nuisance calls, and its enforcement actions and decisions are available on its website. The regulator works with the industry body representing call centres to promote compliance with the abandoned-call rules.
