With Zervant you can easily add a discount on invoices for your customers. On the mobile apps it is currently only possible to add discounts on the invoice total, not on single invoice lines.
You can read more about discounts on invoice lines here Discounts on invoices
How to add a discount on your iOS app
1. Create a new invoice or edit an already existing invoice
2. Click on the field with the invoice number
3. Select discount
4. Decide for discount in % or in your currency
5. Add the discount percentage or discount amount
6. If you add a discount amount, you can choose the amount to include or exclude VAT
7. Click "Save" on the upper-right and continue to edit your invoice
