Can our system still be maintained if the supplier closes or its core team disbands?
No supplier should promise that its company and team will never change. A more reliable design is to make the system transferable to another qualified team from the beginning.
Source code should live in a repository the client can access. Cloud, domain, payment, and application-platform accounts should normally be held by the client entity. Databases need tested backup and export paths; dependencies and licenses need a register; and build, environment, integration, release, rollback, monitoring, and common-incident procedures need current documentation. These assets should be updated at project milestones, not assembled into a source archive only when the relationship ends.
When agreeing deliverables, handover, and ownership boundaries, also compare Can our technical team maintain the system after source-code handover?; the linked guidance adds context that should be considered in the same decision.
Before final handover or termination, run a takeover test. In a clean environment, build and deploy a specified version, restore a representative backup, rotate credentials, and have someone outside the daily development team perform critical operating tasks from the documentation. Record missing permissions, undocumented steps, incompatible dependencies, and recovery results, then close them as acceptance items.
The contract should identify the asset register, update frequency, client access, transfer timing, exit assistance, and any related fee. Escrow may be considered where the client cannot hold current source directly, but it is not a substitute for current data, accounts, build tooling, documentation, and tested release rights. Our transparent delivery standard describes the intended process; the signed handover schedule and successful takeover exercise provide the actual continuity evidence.