Contact your Human Resources department to see if your company has a matching gift program and what it involves. If you're not sure, go ahead and check the box for now, and follow up with your Human Resources department after your donation has been submitted.  Checking the My company will match this donation box does not automatically charge your company, nor does it contact them - it just notifies the nonprofit that this particular donation will be matched at some time in the future, and gives you some extra information in your receipt that you can take to your HR department.