Volunteers who contribute their time to charities certainly aren’t motivated by tax breaks. Many probably don’t even know they’re entitled to deduct the unreimbursed expenses they incur in helping charitable organizations.

Clients who are itemizers may deduct unreimbursed expenses that they incur incidental to their volunteer work. Reg. §1.170A-1(g). So costs incurred in going from home to the charity’s office (or other places where they render services), phone calls, postage stamps, stationery, and similar out-of-pocket costs are deductible as charitable donations.