Calls from 01603 853 XXX — Norwich
Block 01603 853 XXX is allocated by Ofcom to BT, on the Norwich exchange (allocated 2023).
01603 853 XXX is a number block in Norwich, in the historic county of Norfolk, an area with a population of approximately 213,166. Standard landlines in this area use the format 01603 853123, with the first part being the dialling code and the rest being the local number.
This block — 01603 853 XXX — was allocated by Ofcom to BT in 2023. BT either operates the numbers directly or sub-allocates them to resellers and downstream carriers, which is why a single 01603 853 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.
Calls from 01603 853 XXX sometimes link to 'parcel undelivered' or 'card details expired' courier scams. The caller asks you to confirm a delivery address or re-enter card details on a follow-up SMS link. Real UK couriers (Royal Mail, DPD, Evri) handle these via the apps you signed up to, not by phone.
If a 01603 853 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 01603 853 XXX
Is 01603 853 XXX a real UK phone number?
Yes. 01603 853 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 01603 853 XXX number block?
01603 853 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 01603 853 XXX number based?
01603 853 XXX is associated with Norwich. UK geographic numbers historically indicated the location of the line, although VoIP services and number-portability rules mean a 01603 853 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 01603 853 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 01603
Try a different block within the same UK area code:
