After you add an expense, it is possible to delete it.
📎NOTE: You can't delete an expense on the Sage HR app.
Log in to the website version of Sage HR.
Go to your profile (or the employee's profile if you are an admin or manager)
On the profile menu click Expenses, you can see the expense listed under either:
The tab they are under depends on what stage the expense is.
Click on the rubbish bin icon.