Functional requirements

• The concept of Contribution need to evolve towards being an Invoice, and have separate notions for Payments
• Q: should payment plans be implemented as a separate entity, or as a series of Payments for an invoice with a 'Scheduled' status?
• An invoice can combine any number of line items, for example registrations to multiple events for different participants + a membership + a donation (is this a new requirement?)
• Allow any invoice to be:
  • partially paid, eventually through different payment instruments
  • paid in fixed installments (ie. start date, periodicity. installment amount),
  • paid in variable installments (a series of installments with uncorrelated dates and amounts, like a deposit and a obligation to pay in full by a certain date),
  • paid over time with an unknown schedule (ie. concept of a pledge during fund drives for NPR radios or Telethons)
• Allow future payments to be rescheduled, split or otherwise adjusted (might impact the original contribution/invoice, shall we introduce the notion of a 'discount?)
• Q: should we allow a payment to apply to multiple invoices? ie. I registered both my children to camps in separate sessions and now want to pay the full balance on my account.

Technical requirements

• Q: Do not change the naming Contribution (even though the semantics change)?
• Q: released as an extension per LExIM or seed for 4.8 version?
• Q: what is the impact on existing reports?
• Q: what is the impact on the Quickbooks export functions?

UI requirements

• Be very mindful of different spellings: instalment (single l) in the UK, installment (double l) in the US and Canada. This has a lot of UI implications, specifically if included in complex strings - which we might have to split in multiple pieces.
• In the Contributions view screen, have one section for the line items and one section for the payments (right now this is the same section that displays one or the other based on the number of line items)
• Create a screen that would allow debtors to be presented with the list of their open invoices, with payments made to date, and either pay a future installment or add a payment for an invoice.
• Q: what are the payment options that should be made available in the public Contribution pages? Ie. Add 'partially pay' or 'pay in installments' to the existing 'pay online' or 'pay later' choices.