Dynamics Community Forum Thread Details

VAT calculation is not triggered when creating journal line through API

Hi!

I create journal lines with POST businesscentralPrefix/companies({id})/journals({id})/journalLines where I supply i.a. the taxGroup (that is setting the VAT Prod. Posting Group on the line). I have configured my journal and accounts so when my row is created it has:

Gen. Posting Type as Purchase

Gen. Bus. Posting Group as EU

VAT Prod. Posting Group as INRIKES

VAT Bus. Posting Group as EU

And my VAT Posting Setup table has one row with:

Gen. Bus. Posting Group as EU

VAT Prod. Posting Group as INRIKES

VAT % as 25

VAT Calculation Type as Normal VAT

But when my line is created the VAT amount is 0.00. However, if I click the VAT Prod. Posting Group and change it, to anything even the same value as it has, the VAT amount is calculated and updated. It's like the POST to the API doesn't trigger the VAT calculation in the GUI. Is there anyway for me to trigger the calculation through the API? I have tried to PATCH the journal line the taxGroup to see if it triggered but without success.

Also worth noting, when I Preview Posting the G/L and VAT entries are displayed correctly and the VAT is also calculated correctly.

Categories:

Dynamics 365 Business Central

Hello,

The standard journalLines API does not trigger VAT calculation.
Business Central only calculates VAT when a user edits the line in the UI (OnValidate trigger) or when the journal is posted.
That’s why VAT Amount stays 0.00 until you click the field manually, but Preview Posting shows the correct VAT.

There is no API action to force VAT recalculation.
POST/PATCH on journalLines will never run the same calculation logic as the page.

Your options are basically:

Ignore the VAT Amount column – posting will calculate VAT correctly.

Calculate the VAT yourself before sending the line.

Create a small custom API (AL extension) that calls VAT calculation server-side.

There is no standard workaround without customization.

Regards,
Oussama Sabbouh

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