Feature Request: Native Cash Discount (Skonto / Early Payment Discount) Support

Feature Request: Native Cash Discount (Early Payment Discount / Skonto) Support

Summary

InvoiceNinja currently has no native way to handle cash discounts (known as "Skonto" in German-speaking countries). This is a very common payment term in Switzerland, Germany, and Austria, where clients pay a reduced amount if they settle the invoice within a defined period (e.g. 2% discount if paid within 10 days).

Current Workaround

Users currently have to:

1. Record the reduced payment manually
2. Create a credit note for the discount amount
3. Apply the credit to close the remaining balance

This is cumbersome, not intuitive, and the "Apply Credit" option is difficult to find in the UI (especially in v5.13.x). The workaround also does not produce clean reporting or clear audit trails.

Proposed Solution

Add a Cash Discount field to invoices with the following options:

• Discount percentage (e.g. 2%)
• Discount period (e.g. 10 days)
• Display the discount terms on the invoice PDF (e.g. "2% discount if paid by 16.06.2026")
• When a payment is recorded and the discount period is still active, offer to automatically apply the discount
• Book the discount amount as a separate line item or internal adjustment for clean reporting

Why This Matters

• Cash discounts (Skonto) are a legal and tax-relevant transaction in DACH countries
• They need to appear correctly in exports and accounting reports
• Currently there is no clean way to handle this without manual workarounds

Environment

• InvoiceNinja v5.13.24 (self-hosted)
• Region: Switzerland

Related

• Similar to how some accounting tools handle "Skonti" as a separate account/posting type