Not been paid...

[montyburns4]

I don't know the full details but if I'd paid someone to deliver me something I'd be a bit narked if they gave me it back with issues as well to be fair. What are the chances you can fix them quickly?

Yes. The agreement was to do unit testing which all passed on my machine. However regression pulled out issues that weren't related to the upgrade.

[SueEllen]

Ruprect - is your avatar Steve Martin (and Morris Mickelwhite) in Dirty Rotten Scoundrels?

Did the regression tests pass before?

[montyburns4]

Did the regression tests pass before?

They have never done regression on the kits they are testing on. But if they did, it would have the same fail without question

[Lance]

Not been paid...

They have never done regression on the kits they are testing on. But if they did, it would have the same fail without question

So you didn't ask for baseline tests in advance?
I bet you will next time.

You need to talk to them about amicable resolution. They probably would like you to fix it for free. You need to be clear on what you'll do, what you won't do and what you expect to be paid. Put it in writing once agreed and learn from the exercise.

[northernladuk]

I've got a feeling this is going to be a very long thread.

[TheFaQQer]

They have never done regression on the kits they are testing on. But if they did, it would have the same fail without question

Explain that the issues they describe were present before any change as a result of your code - get them to demonstrate their problems working in another environment to show that they are down to your code changes.

[WordIsBond]

What does your contract say about fixing problems? Do you fix them at your cost, or do they pay for fixing them? This is a big question in the context of IR35, and is in HMRC's online tool, but it's also a big question in terms of client relationships. Your first port of call should not be an online forum, it should be to go back and see what, if anything, your contract says.

Then, you need to look at exactly what is your problem and what is preexisting problems, and probably document that thoroughly. Once you know what your contract actually says, and know what is legitimate grounds for complaint and what isn't, you're able to intelligently discuss it with them.

[kaiser78]

And also what was the defined acceptance/completion criteria in the signed contract ? Was it specific enough or have elements of vagueness, hence the situation you are now faced with ?

[kaiser78]

I've got a feeling this is going to be a very long thread.

It doesn't need to be, as the elemental questions have been asked to hopefully inform OP on what he needs to do next.

[d000hg]

So the original contract was to port an existing system to a new technology/platform - a like-for-like rewrite? Plus some bug-fixes to existing issues in the old system?

If that's the case then I can't see it's your responsibility to fix things they didn't tell you were broken if this would be classed as domain knowledge that's unreasonable for you to figure out.

I don't think you answered about contract clauses relating to code ownership... my inclination would be not to release code until payment but it depends what the contract says. Certainly, refusing to do further work until you've been paid for what was already done is not unreasonable.