Hi @emilyk8r ,

After saving the record it cannot be edited. You can do a data repair for that.

You can put a line number when you are entering a line before saving. But, after saving, you cannot change the Line number. As a workaround, you can delete the line and enter a new line as required, but only if the PO is in Planned.

Thanks,

You can change the line number manually. before saving the line.  But as Dumeesha stated  aboveyou cannot change the line number once the line is saved.  

You can delete the line, if the PO header is in a planned status.