Hi jon117, thanks for posting on the Community
We'll be happy to share some guidance on the search function in QuickBooks Online.
The basic search is limited to the last two years of data, while the advanced search has no cap and can filter historical transactions.
If you're unable to find the transaction you need using this feature, try following the steps below instead to locate using the account history. For invoices, these will post to the default debtors/accounts receivable account.
1. Go to Settings and select Chart of accounts (Take me there).
2. Find the account you want to review. Then, in the Action column, select Account history.
3. Select the Filter then select the filters you want to apply. You can use the Find field to search by amount, reference number, or memo.
4. To remove a filter, select the X next to the filter name.
5. Select Apply.
If you find that the advanced search function is routinely unable to locate transactions, please contact our support team so that we can investigate further. Thank you.