Dynamics Community Forum Thread Details

VAT changed after export

We are experiencing issues lately (from 30/06/2026) with VATs being altered when exporting to the BC. I have almost identical payloads that resulted in different rates being calculated. We did not see this happening before.

Sometimes the export uses the Account busProdPostingGroup, sometimes it does not. We would like that when sending taxCode(vatProdPostingGroup) and vatBusPostingGroup BC should calculate the VAT with the rate we are sending. In this case it was vatProdPostingGroup="0" (should be 0% as configured). For this example the Account busProdPostingGroup was 19%.

I have copied only relevant information here below from payloads.

REQUEST 1

{
  "vendorInvoiceNumber": "E004B15A31",
  "vendorNumber": "70081",
  "invoiceDate": "2026-07-03",
  "postingDate": "2026-07-03",
  "dueDate": "2026-07-03",
  "currencyCode": "EUR",
  "pricesIncludeTax": true,
  "vatBusPostingGroup": "INLAND",
  "purchaseInvoiceLines": [
    {
      "taxCode": "0",
      "quantity": 1,
      "unitCost": 7.69,
      "accountId": "9daf21b6-7922-ef11-9f88-002248e64ead",
      "dimensionSetLines": [
        {
          "id": "d49cead2-8729-ef11-9f88-0022485d57fa",
          "valueId": "248b9ab7-a6bb-ef11-b8ea-002248d45827"
        }
      ],
      "description": "-----"
    }
  ],
  "dimensionSetLines": [
    {
      "id": "d49cead2-8729-ef11-9f88-0022485d57fa",
      "valueId": "248b9ab7-a6bb-ef11-b8ea-002248d45827"
    }
  ]

RESPONSE 1

{
"discountAppliedBeforeTax": false,
  "totalAmountExcludingTax": 7.69,
  "totalTaxAmount": 0,
  "totalAmountIncludingTax": 7.69,
}

REQUEST 2

{
  "vendorInvoiceNumber": "E004BA6AE5",
  "vendorNumber": "70081",
  "invoiceDate": "2026-07-07",
  "postingDate": "2026-07-07",
  "dueDate": "2026-07-07",
  "currencyCode": "EUR",
  "pricesIncludeTax": true,
  "vatBusPostingGroup": "INLAND",
  "purchaseInvoiceLines": [
    {
      "taxCode": "0",
      "quantity": 1,
      "unitCost": 7.69,
      "accountId": "9daf21b6-7922-ef11-9f88-002248e64ead",
      "dimensionSetLines": [
        {
          "id": "d49cead2-8729-ef11-9f88-0022485d57fa",
          "valueId": "1b8b9ab7-a6bb-ef11-b8ea-002248d45827"
        }
      ],
      "description": "-----"
    }
  ],
  "dimensionSetLines": [
    {
      "id": "d49cead2-8729-ef11-9f88-0022485d57fa",
      "valueId": "1b8b9ab7-a6bb-ef11-b8ea-002248d45827"
    }
  ]
}

RESPONSE 2

{
  "totalAmountExcludingTax": 6.46,
  "totalTaxAmount": 0,
  "totalAmountIncludingTax": 6.46,
}

I am experiencing other problems as well like the vat is computed twice for example:

"vatBusPostingGroup": "INLAND",
"paymentReference": "VATTEST6",
"purchaseInvoiceLines":[
{
"taxCode":"VAT9",
"quantity":1,
"unitCost":100,
}
 
the account is set to 7% vat and this results into: (VAT9 = 9%)
"totalAmountExcludingTax": 93.46,
"totalTaxAmount": 8.41,
"totalAmountIncludingTax": 101.87,
 
Am I missing something? The behaviors are totally inconsistent.

Categories:

Dynamics 365 Business Central

Hello,

The behavior actually looks consistent with pricesIncludeTax = true combined with the VAT setup on the selected G/L account: in Request 2, 7.69 / 1.19 = 6.46, which means BC first removed the account's 19% VAT from the tax-inclusive unitCost, and then your taxCode = "0" resulted in 0% VAT; similarly, in your other example, 100 / 1.07 = 93.46, after which the 9% VAT code produced 8.41 VAT, giving 101.87 total. So the account's VAT Prod. Posting Group is affecting the net amount before the taxCode is applied. Business Central calculates VAT from the combination of VAT Bus. Posting Group + VAT Prod. Posting Group, and when prices include VAT, changing those groups can also change the calculated net amount. I would therefore avoid pricesIncludeTax = true unless the sent unitCost genuinely includes VAT according to the VAT setup already present on the line; otherwise send net amounts with pricesIncludeTax = false, or ensure the G/L account VAT setup matches the intended taxCode. Since you mention this started around June 30, 2026, I would also compare the exact BC version before and after that date and raise a Microsoft support ticket if the same payload previously behaved differently.

Regards,
Oussama Sabbouh

Quick Links

Leaderboard > Small and medium business | Business Central, NAV, RMS