I have paid myself odd amounts monthly, not on the same date, and now have registered for PAYE and wish to work out the tax/NI on the previous years monthly payments ?

Hello there, @morph1.

At this time, your QuickBooks Online account only allows you to backdate the 2019-2020 tax year. However, you can utilize the HMRC Basic Tools to check your previous years' monthly payments.

You can directly go to these links to work with your PAYE and NI monthly payments for previous years:

For PAYE: http://payecalculator.hmrc.gov.uk/

For NI: http://nicecalculator.hmrc.gov.uk/Class1NICs1.aspx

As always, feel free to visit our QuickBooks Community help website if you need tips and related articles in the future.

Please keep in touch if there's anything else I can do to help you succeed with QuickBooks. I've got your back. Have a great day and be safe.

Thanks - How could I do it for the 19/20 year please and I'll do the one month for 2018 at a later date. Thanks

It's nice to have you back here, morph1.

I'm here to help you with how to backdate your tax for 19/20 years. We'll need to set up the payroll and make sure that your start date is 2019-2020. I'll show you a quick and easy process. Please follow these steps:

1. From the left menu, select Employees.
   
2. Click Let's go from your Payroll dashboard.
   
3. Fill in the following necessary fields and make sure to select the Before radio button.
   
4. Don't forget to add your HMRC gateway credentials:
   > Go to the Company cog at the top right-hand corner, select Account and Settings, and then select Payroll.
   > Fill in your online filing and HRMC reference settings.
   

For 2018, you'll need to do it outside of QuickBooks since the pay period has been locked in the system.

That's it! You should have your backdated tax for 19/20 years.

If you have any other questions, all you have to do is click the Reply button. I'll be here waiting to help you out.