I have the same issue. I sent an FPS with the wrong NI letter for an employee. I have deleted the pay-run in QB and re-run with correct letter. I was about to send the FPS again with letter H (correction to earlier submission) but HMRC have told me this is wrong and will result in a duplicate pay record. Apparently I need to manually add a negative figure to the next FPS in "Employee's NICs this period" (under the old category letter) equal to the over-deduction. Can this be done in QB?
Hi there, @Pandabear1. I can share with you some information about correcting FPS submission in QuickBooks Online (QBO) UK.
At this time, QBO allows you to delete the previous pay run, make an adjustment and run the payroll again to correct the previous submission. Since it may cause duplicate pay records per HMRC, I would recommend reaching out to our Support Team for additional assistance. A live representative can look into your account securely and make any adjustments to correct the NI category.