# 20130902 (Monday, 02 September 2013)¶

## Whether unit prices of sales items include VAT or not¶

The item_vat checkbox on a VatDocument (e.g. an order or an invoice) decides whether unit prices of sales items include VAT or not.

With Lino you can decide this per document. In fact the end-user doesn’t want to decide, they just want it to have the right default value.

Until now the default value was hard-coded and always No.

But sometimes it is Yes.

And this decision should be configurable by local site administrators, i.e. not by modifying application code, only by modifying their settings.py.

Solution so far: I added a new Site configuration method lino.modlib.vat.SiteMixin.get_item_vat() which is documented as follows:

Expected to return the default value for the item_vat field. Called on every new voucher whose model is subclass of lino.modlib.vat.models.VatDocument.

But that’s maybe not a final solution. I guess that there will be system admins who want to decide this when the customer or at the vat_regime has been selected…

Another question is: how to configure whether the prices in the products catalog are maintained VAT included or not. And if they are, then we need a default VAT rate, and remove the VAT when selling to a vat-exempt customer. And be careful when the default VAT rate changes. And must we store this information per product instance?

Meditate… continued tomorrow.