My prices exclude tax. How does nouz read them?

nouz adds the tax Shopify charged to each line of the order. So a shop whose prices exclude tax gets the same 34-line P&L as one whose prices include it. Shopify records which kind every order is, so there is nothing to set up.

In the EU, prices usually include VAT. In the US and Canada, in B2B shops with net prices and in some Shopify Markets setups, they do not. There the tax is added at checkout. Down to the Taxes line, your P&L shows amounts the way the customer paid them, with tax. So on such an order, each line is raised by the tax Shopify charged on it. The shipping takes the rest of the order's tax. The Taxes line then takes the tax out again.

An example with 10% sales tax. You sell an item for $100,00, and $10,00 of tax is added at checkout. Your P&L shows $110,00 in GMV and Gross Revenue, $10,00 on the Taxes line and $100,00 in Net Revenue. That is exactly what you would see for an item sold at $110,00 with the tax inside. Compare-at prices, discount codes and refunds follow the same rule. So a full refund takes back exactly what the order added.

A store can have both kinds of order, for example after moving from net to gross prices. nouz reads each order on its own basis. The Order lines export has a Prices incl. tax column that says which kind each order was. Because nouz uses the tax Shopify charged, the Taxes line holds US sales tax as easily as European VAT.