According to the IRS, 85% of all charitable nonprofits have no paid staff and are run entirely by volunteers.
Volunteers should not receive compensation for their services (receiving it can turn them into “employees” in the eyes of the law).
Volunteer time has value – but volunteers cannot deduct their time on their personal income taxes.
For purposes of a nonprofit’s annual report to the IRS, Form 990, volunteer time is NOT reported as a contribution (see also FASB Accounting Standards 116) but may need to be acknowledged on Part III, Statement of Program Service Accomplishments.
For details about volunteering, see more at Council of Nonprofits