Telemarketer
11 Nov 2025
Calling to speak to someone about gas and electricity
Community overview
Community rating:
Limited data
1 user report · Reported 9 months ago
User Reports (1)
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How to Block This Number
On iPhone
- Open the Phone app and go to Recents
- Find the number 020 3451 7420 and tap the info icon (i)
- Scroll down and tap Block this Caller
- Confirm by tapping Block Contact
On Android
- Open the Phone app and tap the 3-dot menu
- Go to Call history or Recents
- Long press on 020 3451 7420
- Select Block number or Block/report spam
On Landline Phones
Several options are available for UK landlines:
- BT Call Protect - free for BT customers
- TalkTalk CallSafe - free for TalkTalk customers
- Call blocking devices like CPR Call Blocker (available on Amazon)
Register with TPS (Telephone Preference Service)
The TPS is a free service for UK consumers that allows you to opt out of unsolicited sales and marketing calls.
Learn more about TPS registrationAbout this number
Number formats
- UK format: 020 3451 7420
- International: +44 20 3451 7420
Number details
- Number type: Landline
- Number range allocated to: Colt Technology Services
- Area: London
- Area code: 020