Indexo School
The test: 20 points, two versions
Updated on
A test to print: for each lesson, two multiple-choice questions and a two-part calculation, 4 points in all. With all five lessons, it is out of 20.
Two versions, A and B, with different questions and amounts, for two rows of pupils. The marking scheme and answer key are calculated by the Indexo engine using the rules in force on 1 October 2026.
How to use it
- Tick the lessons covered in class: each lesson counts for 4 points.
- Choose version A, print ‘test only’ for one row, then version B for the other.
- Print ‘the answer key and marking scheme’ for yourself.
Allow about fifteen minutes per lesson. Calculators allowed.
Prepare the test
Choose the version, the lessons and what to print, then ‘Print’.
The tool could not be displayed. Reload the page (Cmd + Shift + R on a Mac, Ctrl + F5 on a PC).
Frequently asked questions
What if I have only covered two lessons?
Untick the others: the test is then out of 8 points. The answer key tells you what to multiply by for a mark out of 20.
Can pupils practise beforehand?
Yes: the exercises and quizzes in the lessons are of the same kind, with corrections. The test’s amounts and questions come from the same banks.
What next?
- For teachersThe six-session sequence, the worksheets and the answer keys.
- All lessonsThe five lessons of Indexo School.
The whole Understand section
Understand the calculation
- From gross to net: the calculation explained
- The net pay curve
- The withholding tax key formula
- Your payslip explained
- Decode an official document
- Understand my tax assessment notice
- Tax form 281.10 explained
- Understand my holiday pay statement (blue-collar workers)
- Understand my social contributions notice
- Payroll glossary
- Frequently asked questions
Indexo School
Follow the changes
Sources
Parameters in force on 1 October 2026. Each parameter links to its source, the official one where it exists; a secondary source is flagged as such.
- Instructions administratives : les cotisations de sécurité sociale, NSSO. Cross-checked with: UCM, Securex and the FEB (via the Walloon Public Service) for the basic employer rate in the private sector: 19.88% basic contribution and 5.12% wage moderation contribution, making 25%.
- Taux d’imposition, revenus 2025 et 2026, FPS Finance.
- Vous êtes étudiant : cotisations et précompte, Wikifin (FSMA).
- Règles et taux de TVA : Belgique, taux normal 21 %, taux réduits 6 et 12 %, European Commission (Your Europe).