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
0.2
reducedRate
0.09
registrationThreshold
51130
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 — B1 100 EUR net at 20%
given amount
100
given direction
add
given category
standard
given reverseCharge
no
given annualTurnover
0
expect vatAmount
20
expect grossAmount
120
expect netAmount
100
Case 2 — B2 120 EUR gross back to net
given amount
120
given direction
remove
given category
standard
given reverseCharge
no
given annualTurnover
0
expect netAmount
100
expect vatAmount
20
Case 3 — B3 a hotel night at 9%
given amount
100
given direction
add
given category
reduced
given reverseCharge
no
given annualTurnover
0
expect vatAmount
9
expect grossAmount
109
Case 4 — B4 exactly EUR 51,130 does not yet require registration
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.