How do I add billable expenses to a invoice php api?

Hi there, @api2.

I can see that this needs further verification and requires a specialist in this field. I'm here to help you to get to the right support. 

We have a separate community forum that has this expertise on encoding the correct data to add the billable expense from QuickBooks to your PHP API. They can provide you further information and figure things out. You can also interact with other experienced users, developers, and engineers there.

Here's how to post your concerns on their community page:

1. Go to this link: https://help.developer.intuit.com/s/.
2. Select the Sign in button. Note: You can create one if you don't have an account on this separate community page.
3. Click Help and choose QuickBooks Online.
4. Select the Ask a question button. This is how it looks like:
   
   
    
5. Enter your concern in the box.
6. Submit your post.

I've also added this article for your future reference about splitting estimates to as many invoices as you need: Set up and send progress invoices in QuickBooks Online. This also contains a sub-article about including estimate summaries so that your customer how much they’ve been invoiced for their projects.

I'll be here if you have other concerns or questions. You can click on the Reply button to let me know. Take care always.

Yes, added question as you mentioned.

Thanks,

Kishan