Autonomous System

AS5400 British Telecommunications Limited

ISPActiveUnited KingdomRIPE

AS5400 (BT) is an ISP network operated by British Telecommunications Limited in United Kingdom, registered with RIPE. It has 85 IPv4 prefixes with 734,464 addresses and 40 IPv6 prefixes, which makes it the 544th largest of 82,283 active autonomous systems by IPv4 space.

IPv4 addresses734,464in 85 prefixes
IPv6 prefixes40≈ 7.3 × 10³¹ addresses
Size rank#544of 82,283 active ASNs
Abuser scoreVery Lowunder 0.01% of its addresses flagged · method

Details

OrganizationBritish Telecommunications Limited
AS nameBT
Websitebt.com
Country United Kingdom (GB)
Network typeISP
RegistryRIPE
Abuse contactabuse@eu.bt.net
Registered2002-08-29
Last updated2026-10-15

IPv4 prefixes

85 prefixes · 734,464 addresses
NetworkAddressesFirst – last address
62.134.0.0/1665,53662.134.0.0 – 62.134.255.255
62.180.0.0/1665,53662.180.0.0 – 62.180.255.255
195.100.0.0/1665,536195.100.0.0 – 195.100.255.255
195.163.0.0/1665,536195.163.0.0 – 195.163.255.255
206.73.0.0/1665,536206.73.0.0 – 206.73.255.255
213.15.0.0/1665,536213.15.0.0 – 213.15.255.255
62.5.0.0/1732,76862.5.0.0 – 62.5.127.255
62.102.0.0/1732,76862.102.0.0 – 62.102.127.255
166.49.128.0/1732,768166.49.128.0 – 166.49.255.255
62.173.192.0/1816,38462.173.192.0 – 62.173.255.255
212.162.192.0/1816,384212.162.192.0 – 212.162.255.255
213.194.0.0/1816,384213.194.0.0 – 213.194.63.255
213.236.64.0/1816,384213.236.64.0 – 213.236.127.255
31.95.96.0/198,19231.95.96.0 – 31.95.127.255
82.138.160.0/198,19282.138.160.0 – 82.138.191.255
82.150.0.0/198,19282.150.0.0 – 82.150.31.255
194.213.64.0/198,192194.213.64.0 – 194.213.95.255
195.90.64.0/198,192195.90.64.0 – 195.90.95.255
195.182.96.0/198,192195.182.96.0 – 195.182.127.255
206.73.0.0/198,192206.73.0.0 – 206.73.31.255
212.8.160.0/198,192212.8.160.0 – 212.8.191.255
212.21.192.0/198,192212.21.192.0 – 212.21.223.255
212.31.192.0/198,192212.31.192.0 – 212.31.223.255
212.41.128.0/198,192212.41.128.0 – 212.41.159.255
212.108.0.0/198,192212.108.0.0 – 212.108.31.255
The 25 largest of 85. The API and the database have all of them.

IPv6 prefixes

40 prefixes
  • 2a00:2000::/23
  • 2a00:2200::/25
  • 2a00:2280::/25
  • 2a00:2300::/25
  • 2a0c:7c80::/29
  • 2001:740::/32
  • 2a00:2080::/32
  • 2a00:2081::/32
  • 2a00:2082::/32
  • 2a00:2083::/32
  • 2a00:2084::/32
  • 2a00:2086::/32
  • 2a00:2089::/32
  • 2a00:208a::/32
  • 2a00:208b::/32
  • 2a00:208c::/32
  • 2a00:208d::/32
  • 2a00:2090::/32
  • 2a00:2094::/32
  • 2a00:2095::/32
  • 2a00:2096::/32
  • 2a00:2097::/32
  • 2606:f100:d800::/38
  • 2606:f100:dc00::/38
  • 2402:fb00:8000::/39
The 25 largest of 40. The API and the database have all of them.

Query AS5400 with the API

The ASN lookup returns everything on this page as JSON, including every prefix. ASN lookups need an API key: a free account comes with 1,000 requests a day. 

curl "https://api.ipapi.is/?q=AS5400&key=YOUR_API_KEY"

Any address in its prefixes resolves to AS5400, with or without a key:

curl "https://api.ipapi.is/?q=62.134.0.1"

Other networks of British Telecommunications Limited

AS6871 British Telecommunications Limited2,130,944 IPv4 addressesAS3300 British Telecommunications Limited604,416 IPv4 addressesAS13205 British Telecommunications Limited20,224 IPv4 addresses

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