Invoice Generation Feature Design Template

Tax authorities in the EU, UK, India, and many other jurisdictions require sequential invoice numbering with no gaps. This allows auditors to verify that all revenue is accounted for. If you void an invoice, the number is still consumed. The voided invoice stays in the sequence with a "Void" status and a reason. Skipping numbers or reusing numbers triggers audit flags. Plan your numbering scheme before launch because changing it later creates compliance headaches.

It depends on your market. B2B SaaS in the US and UK typically shows tax-exclusive prices with tax as a separate line item. B2C in the EU often shows tax-inclusive prices (required in some countries). The safest approach is to make this configurable per customer. Your billing system stores amounts tax-exclusive internally and applies the display preference at render time. See the [glossary entry on ARR](/glossary/prioritization) for how different tax display methods affect revenue reporting.

Issue a credit note for the unused portion of the old plan and a new invoice for the prorated charge on the new plan. The credit note references the original invoice. The new invoice shows the prorated amount with the period clearly labeled ("March 15 - March 31, 2026"). This creates a clean audit trail. Some billing providers (Stripe, Chargebee) handle this automatically with prorated line items on the next invoice instead of separate credit notes.

At minimum: seller name and address, buyer name and address, invoice number, invoice date, description of goods/services, quantity and price, total amount, and payment terms. For VAT-registered businesses: seller and buyer VAT numbers, applicable VAT rate, and VAT amount. Requirements vary by jurisdiction, so always confirm with legal counsel for each market you invoice in. Using a [risk assessment template](/templates/risk-assessment-template) can help identify compliance gaps before launch.

Most jurisdictions require 5-10 years. The EU requires 7 years minimum. The US requires 3-7 years depending on the type of record. The safest approach is to retain all invoices indefinitely in an archival system. Storage costs are negligible compared to the risk of not having an invoice when an auditor or customer requests it. Never delete invoices. Void them instead. ---