I'm happy to assist you with recording office design expenses and the payment to the interior designer in QuickBooks Online (QBO), yourbookkeeperhero1. 

QuickBooks Online allows you to easily track your business expenses in addition to sales. By recording your income and expenses, you can get a better understanding of your business and profits. If you have multiple expenses to record, you can directly enter them directly to the account register.

To record expenses in QBO, follow these steps:

1. Select + New. Then select Expense.
2. In the Payee field, select the vendor. If the transaction covers multiple petty cash expenses, leave this field empty.
3. Select the account you used to pay for the expense in the Payment account field and enter the date for the expense in the Payment date field.
4. Choose how you paid for the expense in the Payment method field and enter the preferred label to categorize your money in the Tags field
5. In the Category details section, enter the expense info. Select the expense account you use to track expense transactions from the Category dropdown, then enter a description. You can also enter specific products and services in the Item details section to itemize the expense.
6. Enter the Amount and Tax.
7. If you plan to bill a customer for the expense, select the Billable checkbox and enter their name in the Customer field. 
8. When you're done, hit Save and close.

You can also enter notes in the Memo field. These appear in the account register, on printed checks, and on reports.

For more details and information about managing expenses, you can check out this article: Enter and manage expenses in QuickBooks Online

Furthermore, if you want to learn how to handle bills to be paid later and bills to be paid immediately using bills, checks, or expenses, you can find these in the +New menu in your QBO account: Learn the difference between bills, checks, and expenses in QuickBooks Online

If you have any further questions about recording expenses in QBO, don't hesitate to reach out to us anytime. I'll be happy to help. Have a good day!