What kind of in-kind donations can corporations claim on their taxes?

You mean what kind of items or services can they claim as donations? Well virtually any...however how they are valued is the question. So they can donate say old invesntory...but only to the lesser of cost or market value. Something like services they can donate, but unless they have a basis in it, they can't take a deduction. So a lawyer donating his work pro bobo does NOT get a deduction. A company can't take a deduction for donating the services of their employees, unless they pay the employees. Actually from a corporate/business point of view, there is no real tax benefit available for a donatiopn in most cases, as the same (or sometimes more) of the cost would have been an ordinary expense reducing taxable income had they not donated it (the payroll is a dedcxution, the destroyed invesntory would have been a loss anyway, etc.) Even a cash donation, in most real and practical aspects of business, would have been a deductible advertising cost. Also, in fact, the amount of contributions a Corp can take is limited by many other factors...like the amount of net taxable income they have before taking it, etc. A contribution cannot cause a net taxable loss, whereas a business expense can.