Calls from (020) 3583 XXXX — London
Block (020) 3583 XXXX is allocated by Ofcom to TalkTalk, on the London exchange (allocated 2011).
(020) 3583 XXXX is a number block in London, an area with a population of approximately 9,540,000. Standard landlines in this area use the format 020 3583 1234, with the first part being the dialling code and the rest being the local number.
This block — (020) 3583 XXXX — was allocated by Ofcom to TalkTalk in 2011. TalkTalk either operates the numbers directly or sub-allocates them to resellers and downstream carriers, which is why a single (020) 3583 XXXX prefix can be used by many different organisations. You can verify any allocation against Ofcom's National Telephone Numbering Plan, which is updated weekly.
Calls from (020) 3583 XXXX numbers that ask you to 'press 1' or to call back a different number should be treated with caution. This is a classic premium-rate trap — the call-back number is often in the 09xx range and costs several pounds per minute. Never call back an unfamiliar number you've been instructed to dial.
If a (020) 3583 XXXX number called you and you're not sure who it was, the safest steps are: don't return the call until you've verified it (search the full number online first), don't share personal or financial details, and register the number with the Telephone Preference Service (TPS) if it's a marketing call. Persistent unwanted calls can be reported to Ofcom and the ICO. To block a specific number on most UK mobiles and landlines, you can also enable network-level call screening through your provider.
FAQs about (020) 3583 XXXX
Is (020) 3583 XXXX a real UK phone number?
Yes. (020) 3583 XXXX is part of an Ofcom-allocated UK number block — any number starting with that prefix is a real, dialable UK number assigned by Ofcom to TalkTalk for use on the UK public telephone network.
Who owns the (020) 3583 XXXX number block?
(020) 3583 XXXX is currently allocated to TalkTalk in Ofcom's National Telephone Numbering Plan. The allocated carrier may operate the numbers directly or sub-allocate them to downstream resellers — both arrangements are normal under UK telecoms rules.
Where is a (020) 3583 XXXX number based?
(020) 3583 XXXX is associated with London. UK geographic numbers historically indicated the location of the line, although VoIP services and number-portability rules mean a (020) 3583 XXXX number can technically be used anywhere a CP routes it. For most UK landlines the geographic match still holds.
How do I block calls from (020) 3583 XXXX?
On most UK smartphones, open the recent-calls list, tap the number, and choose 'Block this caller'. UK landlines from BT, Sky, TalkTalk and Virgin Media include free 'BT Call Protect'-style screening you can enable in your provider's app. You can also register your number with the Telephone Preference Service (TPS) at tpsonline.org.uk to opt out of legitimate UK marketing calls.
Other blocks in (020)
Try a different block within the same UK area code:
