# Incompatible Postage

Incompatible postage occurs when a customer purchases multiple items that do not share the same postage type. In this situation, IXO Commerce will calculate the order based on the setting defined in [Site Settings](https://bookstack.iconography.co.uk/books/site-settings "Site Settings") for 'multiple postage calculation.'

[![image.png](https://bookstack.iconography.co.uk/uploads/images/gallery/2025-08/scaled-1680-/OFeimage.png)](https://bookstack.iconography.co.uk/uploads/images/gallery/2025-08/OFeimage.png)