Error
When importing a Business Central Invoice Item, you may receive an error similar to this:
Failed to create record.Control ‘Total VAT Amount’ is read-only.
Reason
The Total Tax Amount on the Business Central Sales Line is not an editable field. The SmartConnect integration will fail with the error if a value is sent to the Total Tax Amount field.
Standard Business Central is going to calculate this amount based on the value of the Total Amount Incl. VAT and the posting groups assigned to the customer and product.
Resolutions
There are two possible approaches to import tax on a sales transaction. Either by using the standard Business Central tax engine, or applied directly from an external system using a standard GL Account line with the total tax collected.
To resolve this error, you need to un-map the Total TAX amount field on the sales transaction line. If you need the Tax Amount on the invoice, map only the Unit Price Excluding Tax amount instead. The Business Central Tax engine will automatically calculate the total Tax Amount for you.
Additionally, to enable the Tax Liable option, use a local constant or a source column with the value set to True.
If you need to import a custom tax amount, you can do it to the GL Tax account line. With this approach we will add an extra GL line to the document to directly assign the tax to a GL tax account.
- In Business Central, publish Page 47 Lines for the Sales Invoice GL Tax Line.
- In the SmartConnect Process > Target tab > Refresh Services.
- Select Entity to Process > Select the service from step 1.
- Map the Target Tax line to a local constant tax account.
