Hello there, @yaseen-elharbi-t.

I'm pleased to share some information regarding expenses in QuickBooks Online (QBO).

In QBO, we have the option to choose our own transaction numbers using the custom transaction numbers option. This adds a field for the invoice number that you may fill out with any number or letter combination. This has a preset numbering scheme and is turned on by default. However, it's unavailable in expenses.

Since it is expected that suppliers will send invoices to various clients, there is no guarantee that the transaction forms you receive will be arranged in a particular order with a set or consistent increment. Transaction numbers are therefore not immediately given to bills and expenses. You'll have to input the numbers on the form.

Additionally, I've included an article that'll help you see the record of your deleted expenses: Use the audit log in QuickBooks Online.

Always know that you can post again here in the Community if you have any other concerns with regard to managing your transactions in QuickBooks Online. Keep safe and have a good one.