Hi there, info2394. Yes, QuickBooks Online allows you to enter transactions for any date as long as that year is not yet reconciled or you haven't set a Closing Date password.
If the 2023 books have been reconciled and a closing date password has been set, there will be a warning box asking for the password. You'll then need to enter the password, and the system will allow the transactions to save.
However, if you need to enter a large volume of 2023 transactions, you can temporarily turn off the lock. To turn off, go to Account and Settings > Advanced tab > Accounting > Pencil icon > Close the books, then switch off > Save > Done.
After entering the transactions, you'll need to re-reconcile the year 2023 to ensure all records are up to date and balanced. You may also refer to your accountant for guidance.
Reply here if you need anything. We're here to help.