old , old invoices, with no payments received. What happens if I delete or void, will this affect transactions from closed periods?

Hello there, @BREF.

Allow me to provide a few information about deleting old transactions in QBO.

There are times when an invoice becomes non-collectible and you need to write it off and declare it as a bad debt so you can clear the invoice.

In the meantime, the option to delete or void old transactions will work. Just remember that this action isn't always advisable for old or reconciled transactions because it will trigger discrepancies on the bank balance.

To get started, you can create an account for Bad Debt in Chart of Accounts and be sure to select Expense as the account type.

Then, follow the detailed steps below in writing off bad debt for an invoice:

1. Go to the Customers tab, then click Receive payments.
2. Select the name of the customer who hasn’t paid you.
3. Leave the amount field at 0.00.
4. If you like, enter a memo at the bottom of the window that you’re writing off bad debt. The memo appears in the customer’s register and prints on statements.
5. Click the Payment column for the invoice that hasn’t been paid.
6. Select the Discount Info button.
7. In the window that drops down, enter the amount of the bad debt in the Discount field and the name of your bad debt expense account in the Discount Account field.
8. Hit OK to record the bad debt.

I've attached these articles to help you after doing the corrections from previously reconciled periods:

• Fix beginning balance issues in QuickBooks Desktop.
• Reconcile previously deleted and re-entered checking or credit card transactions.
• Fix issues while reconciling accounts in QuickBooks Desktop.

Also, I suggest consulting an accounting professional since it involves data from previous Fiscal years.

Let me know if you have follow-up questions about this or anything else. I'm always here to help you. Have a nice day!