The different submission methods are usually tailored to different situations and subscriptions.
- Available to extract and custom accounts you have: e-mail in, mobile apps, direct upload and TripCatcher (UK only).
- Custom only submission ways include: post and Dropbox.
For example, the post-in option is ideal for dealing with large backlogs brought by new clients; the direct upload is great for dealing with many digitised invoices simultaneously (especially with the multiple item PDF option); the Mobile app is irreplaceable when on a business trip.
Even better - ask your clients to submit on day-to-day basis!