Bulk billing and individual customer billing, late fees are not enabled on previous period invoice generation.

If you are creating an invoice for a customer in a previous bill period and the period is not displayed, please uncheck the Include late fees. In bulk billing, this will default as off when the period is selected. This is only required for billing from within a customer's profile.

Monthly invoices can only be created 6 month in the past and up to 6 months in the future.

Annual invoices allow you to create one for the previous year, current year and next year.