Last chance to enroll in this weekend's Paradoxes and Infinity Seminar!

Using Institutional Funds and Tax-Exempt Orders

For the complete list of the Charter Schools for whom we are approved Service Vendors, please see this page.

If you'll be paying with institutional funds, your enrollment cannot be completed on this website (which requires a Paypal or credit card payment). Instead, your enrollment will be completed through a purchase order submitted through your school's Education Specialist, Teacher Facilitator, or the person with a similar title at your school.

Once we have received the purchase order from your school, your child will be immediately enrolled and will receive a "Welcome" message to the email address attached to their account.

If your institution will only cover part of the course or book fees, please contact before the purchase order has been placed.

Purchase Order Guidelines

We accept purchase orders, and they must be submitted via email, mail, or fax to:

Art of Problem Solving
15330 Avenue of Science
San Diego, CA 92128
fax: (855) 430-9531

In addition to your billing information, please include the following information on your purchase order:

If ordering online classes: If ordering paperback books: If ordering online books:
• Student's AoPS username (see below) • Ship-To Address • Student's AoPS username (see below)
• Class Name • Shipping method (see below) • Book Title(s)
• Class Start Date • Book Title(s) & Quantity

AoPS Username

An "AoPS username" is your student’s username that s/he created when registering her/his account on the website. You must indicate your student’s AoPS username on any purchase order that includes classes or online books. If your student does not already have an AoPS username, please create one before placing your order by visiting the Registration page. (The account should be created by a student or parent, not a school official.)


Orders with paperback books are subject to shipping charges. Please indicate your shipping choice on any purchase order that includes paperback books. Prices below are for orders shipped to a single address in the United States.

  • Economy shipping (2-3 week delivery time) for paperback books is free on all orders greater than $100. Online courses, online books, tax, and shipping fees are not counted toward this amount. Economy shipping costs $5 for all orders with less than $100 in paperback books.
  • Priority shipping (3-5 business day delivery time) cost depends on the items to be shipped. For a Priority shipping quote, please visit our Bookstore or email
  • If you would like shipping costs to be billed directly to your FedEx or UPS account, please include this information on your purchase order.
  • Please contact us at for shipping costs to locations outside of the U.S.

Class Drops

For any course with more than 5 classes, students can drop the course any time before the third class session begins and receive a full refund; no drops are allowed after the third class has started. For seminar courses that have only 1 or 2 class sessions, the course must be dropped before the first class session begins; no drops are allowed after the course begins.

To drop a class, the student should go to her/his class homepage and click on the link at the bottom of the page that says "Click here to drop this class." This will initiate the refund process.

Book Returns

Paperback Books: You may return any paperback book within 30 days of purchase. No book returns are accepted after 30 days. Return books to the address listed in "Purchase Order Guidelines" above, and please enclose a copy of your Packing Slip or Invoice with your return. When your returned books are received by us in resalable condition, we will refund the original purchase price. Shipping charges are not refundable.

Online Books: Online book purchases may be canceled within 7 days of activation. To cancel, the student should sign in to her/his account and visit the My Books page. (This page is only accessible to users who have purchased online books.) Below the cover image of any book still in the initial 7-day period there is a button labeled "Cancel Purchase." Clicking this button will initiate the refund process.

Bulk Discounts

We offer bulk discounts for orders of 5 or more copies of a single title (for example, 5 or more copies of the Introduction to Algebra textbook).

  • Save 10% when you order 5 or more copies of a single book title.
  • Save 20% when you order 10 or more copies of a single book title.
  • Book orders over $100 qualify for free domestic economy shipping.

Tax-Exempt Ordering in the U.S.

AoPS is obligated to charge sales tax in any state where we maintain a branch or office, which includes CA, CO, FL, GA, IL, MA, MD, NC, NJ, OH, PA, SC, TX, VA, WA, and WI. Additionally, AoPS is required to collect sales tax in IN, MI, MN, MO, NY, OH, and SC. In all other states we do not collect sales tax at this time. We are also now obligated to collect Goods and Services Tax (GST) in Canada.

If your organization is tax-exempt and is located in one of the states shown above, then you will need to contact to place an order. Please include verification of your tax-exempt status such as a copy of your State Exemption Certificate. You cannot place a tax-exempt order in the AoPS Online Store.

If you are tax-exempt and are not located in the states mentioned above, then you will not be charged sales tax. You can place an order in the AoPS Online Store here at