Raising ownership only when the relationship sours
Every term discussed here is straightforward to agree before work begins and difficult to obtain once there is a disagreement about scope, quality or money. A provider confident in their work will have no issue with you owning the code, holding the credentials and receiving documentation, because they expect to keep the relationship by being good at it rather than by being hard to replace. Reluctance to discuss these terms at the outset is itself the most useful information you will get during a selection process.
Accepting a licence when you needed ownership
There is a real difference between owning the intellectual property in custom work and holding a licence to use it. A licence may permit you to run the software but restrict modifying it, having another party maintain it, or continuing to use it if the agreement ends. For integration code that encodes your specific business rules, that restriction can be severe. Decide deliberately which you are getting, have the clause reviewed if the work is significant, and be aware that a provider reusing a genuine underlying framework across clients may reasonably retain rights in that framework while your specific configuration and logic belong to you.
Documentation delivered as a final invoice item
Documentation written at the end of a project, under time pressure, by someone already working on their next job, is consistently poor. It describes the intended design rather than what was built, omits the workarounds, and skips the operational detail a successor most needs. Require documentation to be delivered progressively with each phase, and verify it by having somebody else follow it. Treating it as a deliverable that gets checked rather than a formality at the end is the only reliable way to get documentation worth having.
Confusing monitoring access with ownership
Some arrangements give you a dashboard showing that integrations are running, which feels reassuring and proves very little. Visibility into whether a job succeeded is not the same as being able to access the code, change it, redeploy it or move it elsewhere. Ask specifically what you could do without the provider’s cooperation. If the answer is that you could watch it run but not alter or relocate it, you have a reporting view rather than ownership, and that distinction matters exactly when the relationship is under strain.
Ignoring the same risk in your own team
Businesses that carefully manage contractor dependency often have an identical concentration internally, where one staff member built the integrations and holds the knowledge. Because they are an employee it feels safer, but resignation, illness or a change of duties exposes the business the same way, frequently with worse documentation because nothing ever needed writing down. Apply the same standard to internal work: shared repository, shared credential vault, documentation aimed at a successor, and a second person who has genuinely performed the routine tasks rather than just read about them.
Holding everything but never testing it
A business can have the code, the credentials and a folder of documents and still be unable to recover, because nobody has ever verified that those materials are sufficient. The documentation may reference an environment that no longer exists, a credential may have been rotated without the vault being updated, or a deployment step may be missing. Run a handover exercise at least annually: ask somebody who did not build the system to make a small change and resolve a simulated failure using only what you hold. Whatever they cannot do is a gap you now have the chance to close cheaply.