I would automatically send organizers to all of my clients every year. A number of them would never bring the organizer back to me when they dropped off their stuff or they would bring it back sealed in the envelope I mailed it in. Last year I quit wasting paper and postage and only mailed the organizers to clients that actually returned them. To be honest, some of the organizers that get completed I wish the client wouldn't fill in because they make such a mess out of them. Sometimes a blank organizer with last year's amounts are easier to work with over the "completed" organizers.
This week's special - free roadrunner dinner with every return (legal disclaimer - you catch it and we'll cook it)