Projects : Setting up the initial receivable and then creating individual invoices

Thanks for posting in the Community, @Janfromearth1.

Based on the information you've shared, you may enter the $100K as a deposit or retainer. This applies if the customer already deposited the amount.

It will be treated as a liability to show that, although your business is holding the money, it doesn't belong to you until it's used to pay for services. When you invoice the customer and receive payment against it, you'll turn that liability into income.

You can refer to this article and proceed to steps 1 to 3 (only) for further guidance: Record a retainer or deposit.

After that, you may now create a customer invoice for each month. Before doing so, make sure that you've already set up the project. If you haven't done it yet, here's how:

1. In QuickBooks Online (QBO), go to the Projects menu at the left pane.
2. Select New Project.
3. In the Project Name field, enter the project name.
4. Pick the project customer from the Customer dropdown.
5. Add any notes or details about the project in Notes.
6. Hit Save.

For more insights about managing Projects in QBO, please visit this article: Set up and create projects in QuickBooks Online.

On the other hand, if the funds if not yet deposited, you can still enter the $100K as the beginning invoice for the Project. Then, use it to received payment every month instead of creating another invoice to avoid duplicates.

Reach out to me in the comment section below if you have any other concerns. I'm always happy to help. Have a great day!

Remember, the grantor does not release any funds until the monthly invoice for materials or services.  Recording it as a deposit would create an offsetting asset, usually cash.  I like the way you are thinking though. Thank you