Unreimbursed,

Directly connected with the services,

Expenses you had only because of the services you gave, and

Not personal, living, or family expenses.

Car expenses. You can deduct unreimbursed out-of-pocket expenses, such as the cost of gas and oil, that are directly related to the use of your car in giving services to a charitable organization. You cannot deduct general repair and maintenance expenses, depreciation, registration fees, or the costs of tires or insurance.

If you do not want to deduct your actual expenses, you can use a standard mileage rate of 14 cents a mile to figure your contribution.

Out-of-pocket expenses. If you render services to a qualified organization and have unreimbursed out-of-pocket expenses related to those services, you can satisfy the written acknowledgement requirement just discussed if:
You have adequate records to prove the amount of the expenses, and

By the required date, you get an acknowledgement from the qualified organization that contains:

A description of the services you provided,

A statement of whether or not the organization provided you any goods or services to reimburse you for the expenses you incurred,

A description and a good faith estimate of the value of any goods or services (other than intangible religious benefits) provided to reimburse you, and

A statement of any intangible religious benefits provided to you.