Hi Emre,
You have the right questions so let me try to explain.
What happens when we create a menu that contains a pizza and a drink? We handle menus on a single product called "Pizza Menu" with a single price and it decreases inventory as it listed on it's own receipt. Normally pizza menu costs less than items total when sold seperately.
If we can't separate food from drinks and treat it as one product (Pizza Menu) than we need to calculate state tax and local tax on the final price of that product. That is why we don't use that combination as a single product but separate Pizza and drinks on the bill (why pay bigger tax ?).
How do you handle modifier taxes? For example some users create "+ chips" modifier to "beer" and add x price to beer price when selected. We use modifiers there because when chips bought with beer it's price will be less than normal price. Think it as a promotion
This issue is similar like above and thus we have that separated on the bill. For cases like this and Pizza Menu we can use different price list for separate products (like for any promotion).
The thing is that tax is always calculated from final price that customer pays and if we can't separate products which only have state tax from those that also have local tax than we need to pay both taxes for that product.
How do you calculate discounts? Should it decrease the final price or the net price? For example if we sell €10 alcohol drink and add %10 discount how we'll calculate tax?
Discounts are decreasing final price. If we give 10% discount on 10 € price than final price is 9 € and on that price taxes are calculated. If there is a number of products on bill discount and taxes are calculated on every product to get total for both price and taxes.
How should we handle taxes for servicing fees? For example some restaurants adds %5 servicing amounts to tickets. What will be the tax details for €10 drink sale + %5 servicing amount?
We have another case for tips. Do you pay tax for tips? How should we handle it?
Every single product or service has state tax so servicing fees and tips have state tax if they are on the bill.
For that reason nobody in Croatia is putting a tip fee on the bill and rare are using servicing fees.
Tip is something that is left for customer to decide and servicing fee is inside a final price (indirectly since it is not specified separately).
If I didn't explained something in some understandable way let me know and I will try with some example.
