[ For the provision of IT services, it was my experience that it is a standard warranty term that, for example, a service provider warrants that the services provided contains no errors or, in the case of software code, the errors are not such that they would put certain crucial infrastructure at risk or are below a specified threshold.
That’s laughable. No-one would sign a software contract that warrants no errors, or errors below some sort of a threshold. If they did, that would be a sign they don’t know what they’re doing and that would be a massive risk.
Certainly lawyers give it a go, because they don’t understand the industry. But these clauses had to go because no-one would agree to them. Especially in Central Government - those contracts are much better these days.
All you can warrant is that you apply skill and expertise, use reasonable good practice, and you don’t act without due care and and attention.