Writing your own Ticket
This would seem like the perfect success story. Write your own ticket and you can have what you want. This has come up frequently in the last few years. Organisations are delegating the Quality Assurance, Testing, and Test Planning to the organisation supplying the software or solution. It seems like a perfect recipe for success. Just test what you already have in the software and have promised to supply and everything will be okay.
The reality is not quite what it seems. The Test Plan is written, the testcases are completed and executed and then comes review time. At this late date, the client suddenly decides this is not what they want or that the testing was incomplete or insufficient.
With no warning the solution provider is now scrambling.
Don't get caught in this!
The solution is the same as before. Anticipate what is likely to be asked for and prepare for it. You may not anticipate everything, you may not tell the client all that you have done, but you will be ready when they ask.