Good to read that @QFSteve suggestion fixed your present situation but there is a disability in not being able to fix more complicated scenarios.
What @QFSteve recommends is useful if your invoice is a simple arrangement but if you have a more complex invoice with a few nominal ledger codes and those lines require amending that option is unavailable currently.
The option to amend the nominal coding per line would make sense to provide an easier way of correcting an input error. This type of accounting correction has already been discussed on this forum and I recently wrote about “An apple and two oranges” about amendments to credit notes that also are “locked” once actioned.
Mistakes happen that could be better reported when we are allowed to fix such errors.
PS @QFSteve My response to [@Cartwrightj could be considered for re-allocating to a “Feature Request” but there are already more than 1,400 such requests; however when looking at the topic; only “Planned”, “Under Construction” and “Implemented” are the filters but not “Outstanding feature requests”.
I hope you understand my frustration as I get more stressed when dealing with QF actions that do not allow an easy fix “locked” actions seem something relating to an HMP…nothing but stuff HMP Slade https://cdn.comedy.co.uk/images/library/comedies/300/p/porridge_200.jpg great acting from a crew that worked as a team!