How to keep track of payment made for cancelled event?

It's nice to see you again here in the Community, @finance139.

I'd be pleased to help you manage the payment that you received from your customer.

You can create a credit memo in the system. This way, you can issue a refund if the customer will ask for the money or apply the credit to the next invoice if they're going to reschedule it.

To create a credit memo:

1. Select + New.
2. Click on Credit memo.
3. In the Customer dropdown, select the customer's name.
4. Enter the credit memo details, such as the date and the amount. 
5. When you're done, select Save and close.

If the customer reschedules the event, you can simply apply the credits to the outstanding invoice.

Here's how:

1. Select + New.
2. Click on Receive payment.
3. In the Customer dropdown, select the customer.
4. From the Outstanding Transactions section, select the open invoice you want to apply the credit memo to.
5. In the Credits section, select the credit memos you want to apply.
6. For the open invoice in the Payment column, enter how much of the credit you want to apply.
7. Leave the Payment method, Reference no, Deposit to, and Amount received fields blank.
8. Fill out the rest of the form, including the Payment date.
9. Make sure the total is correct after applying the credit memo.
10. When you're done, select Save and close.

If the customer wants a refund, you can always follow these steps:

1. Select + New.
2. Select Expense, Add expense or Check. 
3. Select the customer you want to refund from the Payee ▼ drop-down.
4. From the Payment account ▼ drop-down, select the bank account where you deposited the overpayment to.
5. On the first line of the Category column, select Accounts Receivable.
6. Enter how much you want to refund in the Amount field.
7. Fill out the other fields as you see fit, then select Save and close.

For complete details about managing customers payments in QuickBooks Online, you may utilize these resources: 

• Record a customer refund in QuickBooks Online
• Learn how and when to give a credit memo or delayed credit to customers

Know that you can always get back to me if you need more help with invoices or payments. I'll be around to provide continued support. Take care!