First, you need QuickBooks Online PLUS plan, to have prepare and print 1099s feature.
To assign more than one account from your company Chart of Account:
From the home page screen > go to blue navigation bar on the left > click Vendors tab > Prepare 1099s button (upper right side) > Assign Accounts > Select the box number > Under Account, click Select Multiple… from the drop down menu > Select from list > Add to Include in 1099 Box> OK > OK.
Helpful tip: after you click OK, under Accounts it’ll just say “Select Multiple…” , it won’t list all the accounts that you had selected.
