How does licensing work for a product created for another company that will not be taking revenue, but paying for the application?

I currently use unity, and am interested in using unreal.

We create applications for training and simulations for company’s., this can be 3D walkthroughs or VR/AR

They are not collecting revenue but are paying us to make the application. So effectively a lump sum at the end of the project.

I was unsure of licensing and wondered if anyone could assist

Thanks

Dan

Typically, when you "sell’ a software product, you are not actually transferring ownership interest in the software, but selling a license to use the product. Provided you are using this model, you will not owe any royalties for custom work-for-hire products that you develop for and distribute to a company. Please also note that these distributions are limited to object code (executables) only. Section 1(A)(b) of the Unreal Studio EULA provides some pretty clear language on this.