020 3821 5011 +44 20 3821 5011
Landline number from London, range allocated to Colt Technology Services · Also written +44 20 3821 5011
No reports yetNobody has reported 020 3821 5011 on Who Calls You yet.
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About 020 3821 5011
020 3821 5011 is a UK landline number from London (area code 020). It sits in the block 020 3821 xxxx, which Ofcom allocated to Colt Technology Services on 17 April 2015. Nobody has searched for it on Who Calls You in the last 30 days. There are no reports about it yet: if it called you, you can be the first to say what the call was about. Calling it back costs the same as a normal UK call. We first listed it on 6 November 2026.
Number details
- UK format
- 020 3821 5011
- International
- +44 20 3821 5011
- No spaces
- 02038215011
- No spaces with +44
- +442038215011
- Number type
- Landline
- Location
- London
- Area code
- 020
- Range allocated to
- Colt Technology Services
Cost to call: Normal rate · Landline (02). A normal UK landline call, included in the minutes of most landline and mobile plans. UK call costs
Landline numbers for London (020), Cardiff (029), Northern Ireland (028) and a few other areas. Calls cost the same as a normal UK landline call.
Network details come from UK numbering allocations. The number may have moved to another provider since, and this does not show who made a call.
Numbers in the same range (020 3821 xxxx)
020 3821 5011 is in the number block 020 3821 xxxx (10,000 numbers), allocated by Ofcom to Colt Technology Services on 17 Apr 2015.
No other numbers from this block are on Who Calls You yet.
Companies and call centres often use numbers from one block, so reports about nearby numbers can be a useful hint. They are not proof about this number: blocks are shared, and numbers can be moved to another provider.
Recent activity
Last 30 days: 0 lookups and 0 reports on Who Calls You.
No reports in the last 30 days.
Reports about 020 3821 5011
No reports yet. If 020 3821 5011 called or texted you, your report helps other people decide whether to answer.
Report 020 3821 5011
What you should do
- Do not share personal or bank details with an unexpected caller. Banks, HMRC and the police never ask for PINs, passwords or one-time codes.
- Do not call back blindly. If the caller claims to be a company, contact it on the number from its official website, your card or a letter. For your bank you can call 159. Should you call back an unknown number?
- Block the number if the calls are unwanted (see below).
- Report it above, and report scams to Action Fraud. Forward scam texts to 7726 for free.
Caller ID can be faked. Scammers can make any number appear on your screen, including real numbers of real businesses or people. A report here is information to help you decide, not proof of who called.
Questions about 020 3821 5011
Who called me from 020 3821 5011?
020 3821 5011 is a UK landline number from London, range allocated to Colt Technology Services. Nobody has reported 020 3821 5011 on Who Calls You yet. It is also written as +44 20 3821 5011, 02038215011 or +442038215011. We do not show who owns a number. Caller ID can be faked, so check the reports and never share personal details with a caller you do not know.
Is 020 3821 5011 a scam?
There are no reports about 020 3821 5011 yet, so we cannot say. Be careful with unexpected calls asking for money, passwords or bank details, and add a report if this number called you.
How do I block 020 3821 5011?
On iPhone open Recents, tap the (i) next to the number and choose Block Caller. On Android open the call log, press and hold the number and choose Block. On a landline, ask your provider about free call blocking such as BT Call Protect.