| Date | IP Address |
| 2024-05-30 | 13.42.117.209 (ClassC) |
| 2024-06-08 | 13.42.244.51 (ClassC) |
| 2024-10-20 | 13.42.207.136 (ClassC) |
| 2024-11-04 | 13.43.9.35 (ClassC) |
| 2024-12-28 | 18.134.39.165 (ClassC) |
| 2025-05-07 | 13.41.208.200 (ClassC) |
| 2025-06-30 | 18.134.38.230 (ClassC) |
| 2025-08-27 | 13.134.30.128 (ClassC) |
| Date | Domain | IP |
| govuknotify.de-sina3.communications.national.nhs.uk | 2024-05-30 | 13.43.187.93 |
| api.de-jara8.communications.national.nhs.uk | 2024-05-30 | 13.43.158.227 |
| apimmock.dev-base.communications.national.nhs.uk | 2025-06-01 | 18.171.139.121 |
| api.dev-nhsapp.communications.national.nhs.uk | 2024-12-27 | 3.11.121.12 |
| api.uat-letters.communications.national.nhs.uk | 2024-05-30 | 35.178.121.74 |
| govuknotify.uat-letters.communications.national.nhs.uk | 2024-05-30 | 13.42.117.209 |