Two Customers with same tax exempt number in AX 4.0

Hi together,

We have in AX 4.0 two Customers with same tax exempt number. Now I have the task of making it again for other clients, but I get an info logo with the information that two clients can not have the same same tax exempt number.

there is one parameter setting?

Thanks a lot in advance.


They cannot legally have the same exempt number, there is no parameter to allow this for multuple entry for different customers.


It is one customer with two Addresses, therefor different Customers IDs.



I will I allowed that two Customers have the same VAT:

boolean checkVATNumUsed()
boolean ret = true;
CustTable tmpCustTable;

if (TaxParameters::find().VatBookEnable == NoYes::Yes && this.VATNum)
select firstonly tmpCustTable
where tmpCustTable.RecId != this.RecId &&
tmpCustTable.VATNum == this.VATNum;
if (tmpCustTable.RecId)
ret = checkFailed(strfmt("@SYS79490",fieldpname(CustTable, VATNum)));
return ret;

IF excluded:

// if (tmpCustTable.RecId)
// {
// ret = checkFailed(strfmt("@SYS79490",fieldpname(CustTable, VATNum)));
// }

After insert the VAT–> activate it again.


One customer with two addresses only needs one customer record and one exempt ID with multiple addresses.