The article from accounting firm Watkins Meegan specifies 3 base conditions that your electronic receipt storage must meet.

1. Sufficient security to insure the integrity of the scanned receipts.

2. An effective indexing system that allows you to access the receipts when needed.

3. Keep originals for at least one year to verify electronic records.

Fuzion covers numbers 1 & 2 easily. User login protects access to the image files through Fuzion, and no user has root access to the server. Receipts are attached to the applicable expense report, so you can get them instantly when needed. We'll leave storing the originals up to you!