If you head to your clients and take a look at the 'Recent charges' on their membership you may sometimes see that there are more than one charge in the same month for a monthly membership for example.

If this is an auto-payment charge, this could be due to a delay from the bank for example so two charges end up being charged in the same month.

If this is a manual payments membership, this would be due to more than one membership charge being recorded in a month.

You will be able to keep on top of this as the recent charges will list the month/ months this charge is for so you will be able to keep track.

Please view the guide on displaying the billing period on recent charges here.