Advance and final invoices: keep the remaining balance clear

For longer repairs, installations or delivery projects, an advance payment can support cash flow. It also creates a second job: when the work is complete, the order, invoices issued, payments received and final invoice must tell the same story. This is an operational guide for German B2B businesses, not tax or legal advice.

Make the order the calculation baseline

Keep one baseline per job: agreed scope, net order value, VAT rate, approved changes and contact. An advance invoice is a checkpoint, not a replacement for that baseline.

The statutory invoice information is set out in section 14 of the German VAT Act. The timing of receipt can matter for VAT on advance payments; see section 13. Ask your accountant or tax adviser about an actual case.

Use four columns, not one open total

Keep a short job ledger: order net value, each advance invoiced, each advance received, still open. It prevents a frequent mistake: treating every issued advance invoice as paid.

Record the document number, gross/net/VAT amount, issue date, due date, payment date and job reference for each advance. If scope changes, record the approval before changing the baseline.

Calculate the balance transparently

This calculator is a planning aid for one VAT rate and one already paid gross advance. It shows the balance under those assumptions. It does not replace accounting logic, rounding checks, a review of work performed or tax advice.

Then check the chain, not just the ending number: do issued documents match the archive? Do payments match the bank? Are there discounts, retentions, credit notes or partial cancellations? Resolve those before the final invoice rather than manually forcing a balance.

Run the final invoice as a reconciliation

1. Record acceptance or completion of the work.
2. Compare the order with approved changes.
3. Check advance invoices against payments; flag open or duplicate payments.
4. Prepare the final document with a traceable reference to the order and advances.
5. Have a second person compare document numbers, figures and VAT treatment with the job file.

Example from service work

A business agrees 5,000 € net plus 19% VAT for an installation repair. After materials are approved, it receives a gross advance of 1,785 €. The internal ledger links that receipt to the advance invoice. Once the work is complete, the team checks for changes, deviations and further advances, then prepares and reviews the remaining amount. The value is not the formula alone: every figure points back to an order, document and payment.

Send checklist

• Is completion or acceptance documented?
• Are all approved changes included?
• Have invoices and payments been reconciled separately?
• Does the balance match the documents and job record?
• Has a second person checked numbers, VAT and totals?

The German Ministry of Finance explains e-invoicing and retention basics. Your own accounting process and adviser remain decisive for a specific case.

Questions

Is an advance invoice the same as a payment?

No. A document can be issued before money arrives. Keep invoice and payment status separately.

Does the calculator work with multiple VAT rates?

No. It assumes one VAT rate and one paid gross advance. Mixed rates or correction documents require professional review.

What if the order changes?

Record and approve the change first. Then update the baseline and review issued documents instead of overwriting the balance.