The Authority intends to procure Systems Integrator (SI) implementation services through the Government Commercial Agency (GCA) Technology Services 4 framework, using the Lots 2 and 5 matrix combination (2.5). As part of its Preliminary Market Engagement (PME), the Authority will hold an online supplier engagement event on Monday 5 October 2026, from 14:30 to 17:00. Suppliers appointed to the relevant Technology Services 4 Lots 2 and 5 matrix combination (2.5) who wish to participate should register their interest by emailing TESProc@ukho.gov.uk and providing: •organisation name; •attendee name(s); and •attendee email address(es). Registrations should be received by 10:00 on Monday 5 October 2026. Following registration, suppliers will be provided with joining instructions for the online event and a supplier briefing pack containing further information on the proposed requirement and the areas on which the Authority is seeking market feedback. Participation in the PME does not constitute participation in any subsequent procurement and does not commit the Authority to proceed with the proposed procurement.