Integration documents failing due to VAT calculation issues

Value-added tax (VAT) is configured with a set of rules in Dynamics NAV and these rules are created using two types of VAT Groups:

1. VAT Business Posting Groups
2. VAT Product Posting Groups

For each combination of VAT Business Group and VAT Product Group, a VAT % is specified, this is the basis of the VAT configuration and it's called the VAT Posting Setup.

When creating a Customer or a Vendor in Dynamics NAV, the user will assign a VAT Business Posting Group to the account, this is a mandatory field required for posting and becomes the default group used when calculating VAT on documents created against this account.

There are 2 fundamental business rules when working with VAT:

1. When a Customer or Vendor is defined as Exempt from VAT, documents with VAT will not be allowed on this Customer or Vendor.
2. When a Customer or Vendor is defined as Vatable, documents can be posted with or without VAT using this Customer or Vendor.

When creating documents in Chase, the default VAT Business Group is used from the Customer or Vendor but it's possible for a user to override the VAT on line level on the Chase document.

Documents that fail because of a VAT calculation is as a result of a document in Chase where VAT is added to a document but the Customer or Vendor has been configured in Dynamics NAV not to allow VAT.

To rectify this, please take one or more of the following corrective actions:

1. If the document is meant to have VAT, check and correct the VAT Bus. Posting Group on the Customer or Vendor in question and make sure the VAT Bus. Posting Group selected on the account is a group that allows VAT to be posted to the account. This can be done by re-opening the account for editing in Dynamics NAV, updating the VAT Bus. Posting Group and approving the account again. Once the VAT Bus. Posting Group has been amended on the account, reset the status of the document to allow the integration to retry the document.
2. If the document incorrectly calculated VAT in Chase, adjust the VAT on the document in Chase and reset the status of the document to allow the integration to retry the document.
3. To reset the status of the document in Chase, follow these steps:
   1. When working with Sales documents, set the status to Issued.
   2. When working with Supplier documents, set the status to Captured.