BT (British Telecom) IP Lookup

BT (British Telecom) operates the following Autonomous System Numbers (ASNs): AS2856, AS5400. BT operates AS2856 (BTnet UK Regional) and runs one of the UK's most extensive fiber networks (Openreach); BT's wholesale infrastructure means many other UK ISP IPs physically route through BT's network. Use our IP lookup tool to identify which specific ASN a BT (British Telecom) IP belongs to.

BT (British Telecom) holds multiple IP address blocks allocated by its regional internet registry. These blocks are announced via BGP under AS2856 and AS5400. You can identify BT (British Telecom) IP addresses using our IP lookup tool — enter any IP and check if the ISP/ASN fields show BT (British Telecom).

Enter the IP address in our IP Lookup tool. The ISP and ASN fields will show whether the IP is registered to BT (British Telecom) (look for AS2856 or AS5400). You can also use our WHOIS Lookup to query the IP's network registration directly from the RIR database.

BT (British Telecom) provides internet services in: United Kingdom, Global (enterprise via BT Global). IP geolocation for BT (British Telecom) addresses shows the registered location of the IP block, which may differ from the user's actual city.

BT (British Telecom) is a mixed (residential + mobile + enterprise) — its customer IPs are generally classified as residential or mobile, not VPN/proxy. However, customers may run VPN servers on BT (British Telecom) IP addresses, which can cause individual IPs to be flagged.