This should work for you

select j.JobNumber,j.JobType,j.ProductType,j.Date,ca.DateOfCheckBeforeInstallation,ca.CheckDoneBy
from JobsTable j
cross apply(select top 1 p.DateOfCheck,p.CheckDoneBy
            from ProductChecks p
where...

This has done the trick, many thanks for your help on this. 🙂

Awesome, thank you for your help. That has done the trick.

Excellent, thank you that has sorted it. Not quite fully understanding what the COALESCE part does but it does what I need it to.