Yes, it is possible to record additional time to a Fixed Price task that has been invoiced.
Have a look at similar frequently asked questions or visit our FAQs page for more information
Why can't I see the physical stock in my Xero account even though I have connected Xero and TidyStock together?
Does Tidy support a supplier database with 600+ suppliers?
Does TidyWork handle payroll, or just time tracking for projects?
Can TidyStock be integrated with WordPress for an eCommerce platform?
Can TidyStock show customers' Purchase Order Numbers on the sales tab?