How do I apply a discount to an invoice?

Yes — invoices support discounts at two levels, and either one can only be added while the invoice is still a draft; once it's issued, the discount is locked in.

A header discount applies to the whole invoice total. A line discount applies to a single item on the invoice. Both work the same way, as a percentage or as a fixed amount.

To apply either kind, Nassima needs:

• Discount type (percentage or fixed amount)
• Discount value

A line discount can also be linked to an existing discount code, so you can track which promotion it came from. Creating the discount codes themselves — setting up new promotions or coupons — is covered under Discounts and packages; here, you're just applying one that already exists.

When a payment link is generated for an invoice, an existing discount code can also be carried through to checkout, so the customer sees the same promotion at payment time.

However it's applied, the header discount is capped automatically: it can never exceed what's left of the invoice after any line discounts are already subtracted, and it never brings the invoice below zero.

So you can offer whatever discount makes sense for the situation — Nassima keeps the invoice math correct underneath it.