Have you ever come across old receipts and realized that they were from a business trip you'd taken the previous year or even the year before? You were supposed to have entered them at the time to be recorded as expenses for the year in which you'd taken the trip but somehow those receipts fell through the cracks. Don't panic, you can still record the expenses in the current fiscal year even though they were from a previous year, allowing you to write them off as legitimate costs of doing business.
Record the expenses as bills, either individually or collectively, as one itemized report, dating them from the beginning of the current fiscal year.
In the memo section of the expense report, note that the expenses were from a previous fiscal year. Include the actual dates from the original receipts and list the purpose of the trip.
Reimburse yourself for the expenditures. Because you recorded the receipts as bills, they will be considered accounts payable, which will have a balance until you initiate the transaction that will pay them off, thus the reimbursement.
These steps can be followed if you find older receipts from your current fiscal year. Even though you will be able to record them in the correct fiscal year, to go back a few months or several months and record them will change your month-end reporting for all of the following months. It will be easier to record the receipts in your current month and note their original transaction date because it won't affect your year-end reporting anyway.
If you have the time, you can always go into your previous year to record the expenses in the year in which they incurred. As with the previous tip, though, it will change your monthly reports for that year as well as changing the year-end statement. If you decide to do this, remember to notify your accountant so that adjustments can be made on your tax returns.