Deemed acceptance, in plain language

User acceptance testing is the buyer trying the software before a milestone is treated as earned. The dangerous sentence in older contracts is “payment follows successful testing.” Successful according to whom?

A deemed-acceptance clause picks a side in advance. The supplier hands over a build that can actually be tested. The buyer has a fixed number of days to send a written list of failures, in an agreed format. Silence, after that window, counts as acceptance, and the invoice follows.

Two ways to write it badly are common. The window starts before the environment is reachable, so the buyer’s silence is meaningless. Or the criteria are so vague that the buyer can call any dislike a defect and reset the clock forever. The useful version needs three things at once: a build that runs, a test that could be failed in public, and a form for the complaint.

The path’s UAT lesson walks the sequence. Procurement disputes are a useful classroom prompt for this problem. They are not briefed here, and nothing in this note is a recommendation for a live contract.