Good day, Melissa.

I'm delighted to shed some light on this situation. In QuickBooks Online, applying one payment to two invoices from difference companies isn't possible.

You can split the payment between General Contracting and Lawncare. Another suggestion you can look at is using sub-customers as an alternative solution. This is a great feature if you want to track customers who are apart of a group or specific accounts for a larger company.  

Nonetheless, I highly recommend consulting your accountant. If you don't have one, QuickBooks has a service called Pro-Advisors that can assist you. Simply enter your zip code and browse through all the experts in the area and connect with them. Many even offer free consultations.

Thank you very much for your time. I look forward to working with you in the future. Have a great day!

@mbudd10195 

In GC, set up a liability account called 'Due to Lawncare'.  Split the deposit in GC: $3K to your bank account and $7K to the newly-created 'Due to Lawncare' liability account.  Then issue payment to Lawncare and assign the 'Due to Lawncare' liability account to the payment.  Then, deposit the $7K in Lawncare as if it had been received from the customer.  You can make a note in the memo of the invoice to indicate that the customer's payment was made to GC, hence why the bank deposit is coming from GC and not the customer.

Finally, someone who understands basic accounting and can think for themselves.  Refreshing.