Hello there, @DHBilling.

I recognize you need a hassle-free uploading attachment in QuickBooks Online. I'm here to share more information about these check payments.

Since the only option is to upload them manually, you can look for a third-party application that integrates with QuickBooks Online. There is a list of apps available that offers features that you require for scanning documents. To find the right apps for your business, visit the link: QuickBooks App Center.

However, if you need a convenient way to deposit checks you receive from your customers, Sign up for QuickBooks Payments and QuickBooks Checking and use mobile check deposit. Once approved, you can deposit checks without going to the bank. 

To learn further insights and see the mobile check deposit requirements, feel free to view this article: Find out more about mobile check deposit.

You're always welcome to post your other concerns in this thread concerning handling payments. I'm here together with my colleague to help you out. Take care!