The expressions above read these as $const. They are the figures the annual refresh replaces, so they live as data rather than being written into the formulas — which is what makes a year-on-year change a one-line diff instead of an edit to arithmetic.
Constant
Value
standardRate
0.21
reducedRate1
0.04
reducedRate2
0.1
Test vectors (5)
Every case is executed against this model on each build, by the Java engine and independently by a JavaScript one. A mismatch of a single cent fails the build, so the page cannot ship advertising a figure the model no longer produces.
Case 1 — S1 100.00 EUR net at the general rate
given amount
100
given direction
add
given category
standard
given reverseCharge
no
expect vatAmount
21
expect grossAmount
121
expect netAmount
100
Case 2 — S2 121.00 EUR gross back to net at the general rate
given amount
121
given direction
remove
given category
standard
given reverseCharge
no
expect netAmount
100
expect vatAmount
21
Case 3 — S3 100.00 EUR net at the 10% reduced rate
given amount
100
given direction
add
given category
reduced2
given reverseCharge
no
expect vatAmount
10
expect grossAmount
110
Case 4 — S4 100.00 EUR net at the 4% super-reduced rate
given amount
100
given direction
add
given category
reduced1
given reverseCharge
no
expect vatAmount
4
expect grossAmount
104
Case 5 — S5 reverse charge: the supplier charges no VAT
The whole model as JSON — inputs, outputs, formulas, vectors and sources in one re-runnable document.
This model is published under CC BY 4.0: use it, adapt it, build on it, with attribution. The licence covers the model — the expression of each rule and the arrangement of the catalog. The rates and thresholds are law, and nobody licenses those; the sources above are where they come from.