Medium risk
020 4604 1779
AI Summary
Based on 1 community report
This London number, carried by Colt Technology Services, is being used to impersonate Three mobile network. The caller claims you need a new SIM card and becomes pushy about it, attempting to legitimise the call by sending emails and WhatsApp messages to make it appear genuine. This is a classic impersonation scam tactic designed to gain your trust before potentially stealing personal details or payment information.
Three will never contact you this way out of the blue demanding a new SIM, and legitimate network providers won't pressure you through multiple channels simultaneously. If you receive a call like this, hang up immediately and contact Three directly using the number on your bill or their official website to verify whether there's actually an issue with your account.
Written automatically by AI from the community reports on this page. It does not set the spam score, and it can make mistakes, so read the reports below as well.
1 moderated report
Every report on this page was screened automatically and then approved by a moderator before being published and counted towards the score. How moderation works
Cumulative spam score based on all reports up to each month. Higher percentage means higher reported scam risk. Cumulative spam score based on all reports up to each week. Higher percentage means higher reported scam risk. Cumulative spam score based on all reports up to each day. Higher percentage means higher reported scam risk.
Most helpful reports
1 totalSubmitted by users and shown as written, so wording and spelling are their own. Each report is screened and approved by the CallerCheck Moderation Team before it appears.
Said they're calling from Three network but it isn't. Said I need a new SIM card. Really pushy and trying to send emails and WhatsApp messages to make you think it is Three.
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How this page was checked
This profile is built from community reports, lookup activity and CallerCheck risk signals. It is not written by hand for this number, so the details below show who checks what and when it last changed. The risk score is based on community reports about calls and texts from this displayed number. It is not based on official records of who owns the number.
- Reports moderated by
- CallerCheck Moderation Team
- Safety guidance reviewed by
- CallerCheck Editorial Team
- AI summary
- Generated from approved community reports only
- Last report received
- 07 Apr 2026
- Last reviewed
- Reviewed automatically from current approved report data
- AI summary last generated
- 07 Sep 2026
- Last materially updated
- 07 Sep 2026
What do these dates mean?
Report and lookup dates come from user activity. Review dates show when CallerCheck last checked reports, safety guidance, or risk signals. We use “last materially updated” only for meaningful page changes, not cosmetic changes.
- First seen:
- when this number first appeared on CallerCheck, through its first lookup or report.
- Last report received:
- the most recent approved community report for this number.
- Last lookup:
- the most recent time a user searched for this number.
- AI summary last generated:
- when the AI summary on this page was last rewritten from the approved community reports.
- Last reviewed:
- the most recent human moderation or editorial review, where available.
- Last materially updated:
- the most recent meaningful change to this page: a new approved report, a risk score change, an AI summary regeneration, a moderation action, or a claim or dispute change. It does not move for cosmetic changes.
Sources and safety guidance
- Community reports about this number, screened before they are published or counted. How moderation works
- Ofcom numbering allocation data for the network this range belongs to
- Safety guidance aligned with UK scam-reporting advice, such as Action Fraud guidance, forwarding spam texts to 7726, and the 159 banking helpline where relevant. Where to report a nuisance call
Important limits
Caller ID can be spoofed, so a high risk rating means people have reported suspicious activity involving this displayed number. It does not prove that the registered owner of the number made the call or text. Community reports describe individual experiences and are not official confirmation of a scam. How caller ID spoofing works.
Own or manage this number? If this number belongs to you or your organisation, you can claim or dispute this profile. We review claims, check supporting information, and may update the page if reports appear to involve spoofing, mistaken identity, or outdated information. Claim or dispute this number
About 020 4604 1779
What type of number is 020 4604 1779?
The phone number 020 4604 1779 (also written as +44 20 4604 1779) is a UK landline number originating from the London area in Greater London . Calls to this number are charged at standard UK landline rates, usually included in call packages.
Is 020 4604 1779 safe to answer?
Based on 1 community report, this number has received mixed reports from our community. The current risk score is 62% .
Be cautious when answering calls from this number. Verify the caller's identity before sharing any information.
What this data can and cannot tell you
Everything on this page comes from reports submitted by members of the public about calls and texts that showed this number. Caller ID can be spoofed, so the person contacting you may not be the genuine holder of the number, and a legitimate number can be misused. Before paying anything or acting on a message, check the claim with the organisation involved using contact details from its official website or letters, never the ones in the message itself.
More on nuisance calls
Safety score
1 reportHow this score was worked out
Each report rates the number as safe, unknown, suspicious or spam. The score blends those ratings, giving more weight to the more serious ones, and a number with only a few reports is held closer to neutral until more arrive. Feedback votes on reports can also influence it slightly. Scores of 70% and above count as high risk, 40% to 69% as medium, and below 40% as low. More about spam scores
Details
- Tel Number
- 020 4604 1779
- Country
- 🇬🇧 United Kingdom
- Network
- Colt Technology Services
- Area
- London
- Type
- Geographic
- Coverage
- London and the surrounding area
- Cost to call
- Standard landline rate
- First Seen
- 07 Apr 2026
Network shows the operator this number range is allocated to in Ofcom numbering data, so the caller may be on a different network if the number was moved or spoofed. First Seen is the date this number first appeared on CallerCheck.
Call Types
Breakdown of reported call reasons. Larger segments and bars represent a bigger share of reports.
Location
London, United Kingdom
This number originates from the London area code region. The map shows the general geographic area, not an exact location.
Protection Guides
How to Block This Number
Clear instructions for iPhone, Android, and landlines
Caller ID Spoofing
Scammers can make any number appear on your phone, including your bank's real one. How spoofing works, how to spot it, and what to do if your own number is being used.
Report to Ofcom
How to report nuisance calls officially
Is this your number?
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We review claims carefully and may keep warnings visible where community reports still indicate risk.