Our accountant has asked for a detailed transaction report that will show every entry in each individual Income/Expenditure account for the financial year, can I do this?

It's good to see you here in the Community, steve314.

Yes, it's possible. You'll have the option to run the Profit & Loss Detail report if you want to see an individual transaction for each income/expenditure account in QuickBooks Online.

Here's how:

1. Click the Reports menu.
2. Run the Profit & Loss Detail report.
3. Enter the correct reporting period.
4. Select Run report.
5. You can also click the Customise button if you want to filter the data displayed on your report.

Check out this guide if you want to show only the information needed for your business: Customise reports in QuickBooks Online.

In addition, you can also save the current customisation setting by memorising your report. 

If you need further assistance with reports, let me know. I'll be here to help you.