Hello Stuart,
Thank you for your post.
If I got it right, you would like to exempt from taxes the non-profit buyers. Yes, it's possible to do, please follow these steps:
1. Log in to your Ecwid Control Panel and go to My Sales --> Customers.
2. In the opened window you will see the list of your customers.
3. Click on the pencil icon (
screenshot).
4. The edit mode will open, where you can move the slider to exempt the taxes from the particular customer (
screenshot).
Please note, that in order to use this feature, the customer account must already exist. The customer can create his/her account by pressing the Sign In button in your store. Also, the customer will be asked to create the account/sign in upon placing the order in your store. After that, the customer will appear in My Sales --> Customers tab and you will be able to enable the `Exempt taxes` option for this customer.
That's it. I hope, that the information provided in this post will be useful to you. In case of any issues, please do not hesitate to contact me.
Useful Links: