how do i mark an invoice as unpaid?

I can guide you with marking the invoice as unpaid, @keniccustom. 

If you already recorded an invoice payment, you can go to the invoice, open the payment that you processed, and remove the payment that you processed. 

Here are the steps: 

1. Go to the Sales menu and proceed to the Invoices page. 
2. Find and click the Edit button to open the invoice.
3. Scroll down to the Invoice Total section and click the Payment link.
4. On the Receive Payment page that opens click the Clear Payment button. 

After that or if you haven't processed a received payment transaction, you can record them as bad debt and write them off. 

You'll just have to create a bad debt item from the Products & Services tab, followed by creating a credit memo for it. Lastly, apply the credit memo to the invoice.

Here's how to create a bad debts expense account:

1. From Settings, select Chart of Accounts and click on New to create a new account.
2. Click the Account Type dropdown and click on Expenses.
3. From the Detail Type dropdown, select Bad Debts.
4. Provide all the necessary information. 
5. Select Save and Close.

To create a bad debt item:

1. From your Settings, select Products & services.
2. Click on New, and then Non-inventory.
3. In the Name field, enter Bad debts.
4. From the Income account dropdown, select Bad Debts.
5. Click on Save and Close once done.

To create a credit memo for the bad debt:

1. From the + New button, choose Credit memo.
2. In the Product/Service section, select Bad Debts.
3. Provide all the necessary information. 
4. In the Message displayed on the statement box, enter Bad Debt.
5. Click Save and Close once you're done. 

To apply the credit memo to the invoice:

1. Go to the + New button and choose Receive payment.
2. Set the customer and proceed to the Outstanding Transactions section to select the invoice.
3. From the Credits section, select the credit memo.
4. Click on Save and Close.

Here's more information about recording invoices as bad debt and writing them off: Write off bad debt in QuickBooks Online. 

Then, check out the following article for more information about recording partial and full payments: Record invoice payments in QuickBooks Online.

Let me know if you have a follow-up question about your invoices or any other QuickBooks concerns. I'm always here to assist. Keep safe!

Thank you so much for all that!!! I appreciate it a lot! 

Have a great weekend!!

Cheers!

Thank you so much for all that!I appreciate it a lot!! Have a great weekend!

Cheers!

Thank you for coming back to the thread, @keniccustom.

We're glad to hear that my colleague's response was able to help with managing your invoices. 

This thread is always open if you need further help using QBO features. We're always here to assist you at any time. Have a great day ahead! 

Ok so I went through all the steps and got  to the last part, which I copied below, on applying the credit memo.  Step 3 from the credits section. I don't have anywhere on the page where it says "credits" in order to select the credit memo.

To apply the credit memo to the invoice:

1. Go to the + New button and choose Receive payment.
2. Set the customer and proceed to the Outstanding Transactions section to select the invoice.
3. From the Credits section, select the credit memo.
4. Click on Save and Close.

I'm here to share information about the credits section not showing on the Receive Payment page, Keni.

I appreciate you following the steps provided by my colleague to create a bad debt in QuickBooks Online.

If the Credits section is not showing on the Receive Payment page after creating a credit memo, it can be that the credit has already been applied to another invoice.

I recommend checking the customer profile and reviewing the transactions to see if there is a credit memo applied.

Here's how:

1. From the left menu, choose Customers & leads.
2. Under Customers, select the name of the customer.
3. Scroll down to see the transactions. You can add a filter to show only credit memos by choosing Credit memos from the Type dropdown. It will show Applied under the status if it is already applied.

For future reference, here is an article to help you categorize your online payments and invoices to avoid duplicate entries: Categorize online bank transactions in QuickBooks Online.

Feel free to comment below if you have questions about managing invoices in QuickBooks Online. I'm always here to help. Have a great day.

@keniccustom 

If you have "Automatically apply credits" turned on in Settings (Settings > Automation > Automatically apply credits) QBO will apply the credit when you create it so you won't see it when you try to receive payment.  The invoice should be closed, however.

Also, the advice given by QB employees is only for accrual basis accounting.  If you're on cash basis, you don't have bad debt expense.  You should zero out the invoice or create a credit memo that has the same items at the same cost as the invoice.