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
0.05
registrationThreshold
375000
registrationThresholdVoluntary
187500
Test vectors (6)
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 AED net at 5%
given amount
100
given direction
add
given reverseCharge
no
given annualTurnover
0
expect vatAmount
5
expect grossAmount
105
expect netAmount
100
Case 2 — S2 105.00 AED gross back to net
given amount
105
given direction
remove
given reverseCharge
no
given annualTurnover
0
expect netAmount
100
expect vatAmount
5
Case 3 — S3 reverse charge: the supplier charges no VAT
given amount
100
given direction
add
given reverseCharge
yes
given annualTurnover
0
expect vatAmount
0
expect grossAmount
100
Case 4 — S4 above AED 375,000: registration is required
given amount
100
given direction
add
given reverseCharge
no
given annualTurnover
400000
expect mustRegister
true
expect registrationStatus
required
Case 5 — S5 between the two figures: voluntary registration
given amount
100
given direction
add
given reverseCharge
no
given annualTurnover
250000
expect mustRegister
false
expect registrationStatus
optional
Case 6 — S6 below AED 187,500: registration is not available at all
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.