How to receive payments from 2 parties to one invoice?

Hello, @RedRob. I can help you receive payments by creating two items.

You can invoice the customer for the deductible amount. Then create two line items. The first line item is the service item with the total amount. Then the second line item is the discount item with the deductible amount.

Here's how:
 

1. From the Lists menu, select Items.
2. Select Plus + icon.
3. In the item details, select Discount from the drop-down list under Type.
4. Enter a name for the discount.
5. Fill out all the needed information like the discount amount or percentage.
6. Choose an account for the discount to be associated with.
7. Then select Ok.
    

You can refer to this article for more details on how to add, edit, and delete items in QuickBooks Desktop: Add, edit, and delete items.

You can also ask your accountant if they have a different way of entering this transaction.

Let me know in the comment section if you need anything else. I'd be glad to assist you. Take care!

So you're suggesting that I enter the payment from the ticketing company as a separate sales receipt showing the income, then just discount my client's invoice with that same amount (so the income only shows once).

Seems reasonable.

But still doesn't address the actual fundamental question -- if we invoice client ABC, and two different people are paying for that invoice (ABC pays part, and DEF pays part), how can I enter the payment from DEF towards that invoice and have it reflect that the payment was from the correct person.

I have this same issue.  Have you found a solution?

I understand how important this functionality could be beneficial for your business needs, Meg88. 

The option to add a payment to invoices from multiple customers is unavailable in QBDT. QuickBooks is designed to apply payments to invoices for a single customer at a time. 

As a workaround, we can record the payment separately for each customer. Alternatively, you can accept the full payment from one customer. Then, add a note in the memo that a portion of that payment is from another customer. 

I've added a screenshot for your reference.

At times, we roll out enhancements based on our customer's requests. I suggest sending a recommendation to our product developers. They'll review this idea and might consider updating it in the future.

Here's how:

1. 1. Go to the Help menu and then select Send Feedback Online.
   2. Choose Product Suggestion.
   3. Add the type of feedback.
   4. Type in your feature suggestion.
   5. Once done, click Send Feedback.

    

   For your visual reference, I've attached some screenshots below.

   

    

I'm also adding this article if you'd like to create a more personalized sales form for your customers: Customize invoices, estimates, and sales receipts in QuickBooks Desktop. 

If there's anything else I can help you manage your invoices, or should you consider working with us again down the road, please know that our door is always open.