Yes, with over 70 countries supported around the world, you can provide your conference attendees a toll-free call and make sure they're not going to incur any cost for participating. To turn this feature on, navigate to the Account > Account Settings page. Click on the "Toll-Free International" option and select "Turn On" to activate this service.

Please note: There is a $20 one time charge to activate this feature, also depending on your plan, additional per minute, per caller charges may occur.