I'd be glad to assist you in making sure the memo field will be included when printing your checks in QuickBooks Online, @Canes. 

In QuickBooks Online, the ability to include memos on printed checks is just as easy as it's originally made to be printed together with it. We just have to make sure that we've entered the text we'd like to appear.

On the other hand, if you're referring to the bill payment check, please know that it's currently unavailable in QuickBooks Online. However, you don't have to worry as we've prepared a workaround you can utilize which is to manually enter the memo and I'd love to include the complete process for your convenience:

First, let's open the bill:

1. Go to the Expenses menu then select Expenses.
2. Open the bill you want to print then take note of the memo or copy it.
3. Hit Save and close.

Now when you're ready to pay the bill and print the payment check,
 

1. Hit on the +New icon then select Pay bills.
2. Select the bill by hitting on the checkmark box. 
3. Ensure that the amounts are correct then select Save and print.
4. In the Print Checks screen, select the Bill Payment (Check).
5. Scroll down to the Memo field and type the memo we've taken note of earlier.
6. Select Print check then hit on Preview and print.
7. Review the information. When ready, select Print.
    

Additionally, I've prepared an article you can always refer to in case you encounter printing issues when you encounter the most common printing issues: Fix QuickBooks Online printing issues on browsers for Windows.
 

Let me know if there's anything else you need by leaving a comment below. It's my priority to ensure that you'll be able to include the memo field when printing checks in QuickBooks Online. I'll be willing to lend a hand. Have a wonderful day.