Month end reporting issues

Hi,

I need to perform month end financial reports from my database. I have created a formula so that when I enter the date that the invoice has been paid this then turns it into “MONTH({Invoiced paid by client})”.

I can then group this by month (1, 2, 3, 4 etc) and perform my month end reporting.

However, now that we’ve been trading for a year any invoices that have been created in June 2018 are now being grouped within the June 2019 view.

I think there are two solutions to my problem but I can’t figure out how to do either of them or even if the solution exists!

Either

1. Change the formula to be MONTH & YEAR
   or
2. Move all 2018 records into a different table and/or base

Can’t seem to figure out if either of these are possible.

Please help!

Thanks
Kate