Configurable Invoice Due Dates for Subscriptions

User Story

As a billing or customer service admin,
I want to control or delay invoice due dates for subscriptions, so invoices do not appear past due before the actual billing intent.

Current Behavior

• Due date cannot be edited.

  

• No visible configuration at:

  • Product level

  • Subscription level

• Applies even when:

  • Billing is offline (Not using a payment gateway)

Expected / Desired Behavior

Admins want to be able to define or override invoice due dates.