| W R Berkley Insurance (Europe) Ltd | 02072809000 | 2nd Floor, 40 Lime Street, London, EC3M 7AW, United Kingdom |
| W R Berkley Syndicate Management Limited | 020 3943 | 34 Lime Street, London, EC3M 7AT |
| Wakam UK Ltd | 330 186 76 73 13 | 18th & 19th Floors, 100 Bishopsgate, London, EC2N 4AG, United Kingdom |
| Watford Insurance Company Europe Limited | 350 200 74570 | First Floor, Grand Ocean Plaza, Ocean Village, GX11 1AA, Gibraltar, ZZ9 9ZZ |
| Wellington | | |
| West Bay Insurance PLC | 01227 284700 | Prospect House, Chaucer Business Park , Thanet Way, Whitstable, Kent, CT5 3FD |
| Western Captive Insurance Company Limited | 0035312666000 | Third Floor, The Metropolitan Building, James Joyce Street, Dublin, Z99 9ZZ |
| Westfield Specialty Managing Agency Ltd | 0207 712 7600 | Camomile Court, 23 Camomile Street, London, EC3A 7LL |
| XL Insurance Company SE | 0207 933 7268 | 20 Gracechurch Street, London, EC3V 0BG, United Kingdom |
| XL LM 1209 | | |