Why are my tax items changing with context?

Question

I am creating an invoice via the XML Interface. When I use the following XML, things appear to work correctly.

<?xml version="1.0" ?>
<?qbxml version="12.0" ?>
<QBXML>
<QBXMLMsgsRq onError="stopOnError">

<InvoiceAddRq>
<InvoiceAdd>
  <CustomerRef><FullName>ADAMS, MEG (01689)</FullName></CustomerRef>
  <ClassRef><FullName>Stores:Atlanta</FullName></ClassRef>
  <TxnDate>2014-03-05</TxnDate>
  <RefNumber>R-727</RefNumber>
  <SalesRepRef><FullName>DS</FullName></SalesRepRef>
  <ItemSalesTaxRef><FullName>TI-Zero</FullName></ItemSalesTaxRef>

<InvoiceLineAdd>
  <ItemRef><FullName>400100000403</FullName></ItemRef>
  <Desc>Store Credit SC-000000727</Desc>
  <Quantity>1.00000</Quantity>
  <Amount>513.00</Amount>
</InvoiceLineAdd>

<InvoiceLineAdd>
  <ItemRef><FullName>400100000234</FullName></ItemRef>
  <Desc>PAIR JARS</Desc>
  <Quantity>-1.00000</Quantity>
  <Amount>-475.00</Amount>
  <InventorySiteRef><FullName>4</FullName></InventorySiteRef>
</InvoiceLineAdd>

<InvoiceLineAdd>
  <ItemRef><FullName>TIS-GA</FullName></ItemRef>
  <Desc>Sales Tax</Desc>
  <Amount>-19.00</Amount>
</InvoiceLineAdd>

<InvoiceLineAdd>
  <ItemRef><FullName>TIC-GA-Fulton</FullName></ItemRef>
  <Desc>Sales Tax</Desc>
  <Amount>-14.25</Amount>
</InvoiceLineAdd>

<InvoiceLineAdd>
  <ItemRef><FullName>TIM-GA-Atlanta</FullName></ItemRef>
  <Desc>Sales Tax</Desc>
  <Amount>-4.75</Amount>
</InvoiceLineAdd>
</InvoiceAdd>
</InvoiceAddRq>

</QBXMLMsgsRq>
</QBXML>

Note that all the sales tax items are negative, as is the single inventory item price (this is a return). However, if I reverse the top two invoice lines, the sales tax items all switch from negative to positive in QuickBooks, even though I am still sending them as negatives. Is there a particular reason that sales tax should be context-sensitive? Is this documented somewhere? Is there a workaround? It worries me that QuickBooks is not preserving what I send in.

I can't attach screenshots as I don't have sufficient reputation points.

Answer 1

I'm going to assume that you are using the US edition of QuickBooks as that is the only version that I have access to. This is one of those quirky QuickBooks functions. If you were to manually try to enter this transaction using the UI, you would also get the same behavior. QuickBooks does not allow you to manually enter a negative amount for a line that has a sales tax item.

However, QuickBooks will enter a negative number itself if you add the sales tax item after a taxable negative item, or a subtotal that is a negative amount. If you attempt to change the amount of a sales tax line item after QuickBooks has calculated the amount, you are only allowed to enter a positive number.

If you want to ensure that the amount is correct without relying on QuickBooks calculation for sales tax, you would need to create a credit memo for the returned items (using positive numbers on the credit memo), then create an invoice for the store credit item and apply the credit memo to the invoice.