Calls from 0800 3436 XXX
Block 0800 3436 XXX is allocated by Ofcom to BT, on the UK Freephone exchange (allocated 2001).
0800 3436 XXX is part of the UK's 080x freephone range. Calls to a freephone number such as 0800 343 6123 are free from both UK landlines and mobiles since Ofcom's 2015 rule change. Freephone numbers are owned by businesses, charities and public bodies; the receiving organisation pays for the call.
This block — 0800 3436 XXX — was allocated by Ofcom to BT in 2001. BT either operates the numbers directly or sub-allocates them to resellers and downstream carriers, which is why a single 0800 3436 XXX prefix can be used by many different organisations. You can verify any allocation against Ofcom's National Telephone Numbering Plan, which is updated weekly.
Insurance and accident-claims cold calls remain a heavy source of unsolicited 0800 3436 XXX-prefix traffic. Since 2019 it has been illegal under UK law to make unsolicited cold calls about pensions, and similar tightening is in force for insurance leads. You can register your number with the TPS for free to block legitimate UK marketing calls.
If a 0800 3436 XXX 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 0800 3436 XXX
Is 0800 3436 XXX a real UK phone number?
Yes. 0800 3436 XXX 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 BT for use on the UK public telephone network.
Who owns the 0800 3436 XXX number block?
0800 3436 XXX is currently allocated to BT 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 0800 3436 XXX number based?
0800 3436 XXX is associated with UK Freephone. UK geographic numbers historically indicated the location of the line, although VoIP services and number-portability rules mean a 0800 3436 XXX 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 0800 3436 XXX?
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 0800
Try a different block within the same UK area code:
