Construction billing that fits.
Progress and final invoices with a running total. IONVO deducts the retentions automatically and shows them on the final statement.
The running total, line by line.
Illustrative figures, simplified: the instalments add up, the warranty retention is deducted, and the final invoice shows where things stand.
A running total across all instalments
A progress invoice bills the work done to date and deducts what earlier instalments have already billed. IONVO carries that total across the whole project. You enter the progress, the invoice works out the rest. If an earlier instalment is corrected, every later one follows.
Warranty retention and coverage retention
The coverage retention (Deckungsrücklass) secures the client during the build; the warranty retention (Haftrücklass) does the same afterwards, for the warranty period. Both are a percentage in the contract, and IONVO deducts them on every invoice.
On the final statement they are shown apart: the coverage retention is settled with the final invoice. The warranty retention stays as an open amount, with the date it is released, until the warranty ends.
VAT and reverse charge
Construction services for another construction business fall under § 19 (1a) of the Austrian VAT Act: the tax liability shifts to the recipient, the invoice shows no VAT and carries the statutory note. IONVO recognises the case from the customer and the service, calculates net and adds the note. You do not have to look anything up.
For every other job, IONVO applies the right rate and shows the VAT on each progress and final invoice.
How it reads on the invoice.
Baumeister Beispiel GmbH
Werkstraße 12
1230 Wien
VAT ID ATU12345678
Invoice to
Wohnbau Beispiel GmbH
Am Kanal 7
1210 Wien
- Invoice number
- AR-2026-0142
- Invoice date
- 04.09.2026
- Period of performance
- 01.07.2026 to 31.08.2026
Project New residential building, Feldgasse 12, 1210 Wien
| Item | Work | Quantity | Unit | Unit price | Amount |
|---|---|---|---|---|---|
| 1 | Earthworks, excavation of the building pit | 420,00 | m³ | 38,50 | 16.170,00 |
| 2 | Structural work, reinforced concrete basement walls | 186,00 | m² | 148,00 | 27.528,00 |
| 3 | Structural work, slab above the basement | 210,00 | m² | 96,00 | 20.160,00 |
| 4 | Carpentry, roof truss | 1,00 | lump sum | 24.800,00 | 24.800,00 |
All amounts in EUR, net.
- Work performed to date
- 88.658,00
- less 1st progress invoice
- − 34.500,00
- Work billed in this invoice
- 54.158,00
- less coverage retention 5 %
- − 2.707,90
- less warranty retention 3 %
- − 1.624,74
- Subtotal net
- 49.825,36
- plus VAT 20 %
- 9.965,07
- Amount due
- 59.790,43
Payable by 18.09.2026 without deduction. The warranty retention is settled with the final invoice.
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Measurements and line items
A project is made of line items with a quantity, a unit and a unit price. You enter the progress per item, as a percentage or as a measured quantity. A change order is added as its own item and raises the contract value without touching old invoices. On time-and-materials work, the signed hours and the material from the site count.
Part payments
If the client pays an invoice in parts, you book each payment against it. The open amount goes down, the retention stays shown apart. The list of open items shows, per invoice, what is still missing and for how long.
The retention works itself out.
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