Shipping & Returns

Our family here at Math4Sale, Inc. really appreciates you. We work very hard to do our best, but unfortunately returns and exchanges happen from time to time as you can imagine.

This is why we stand behind all of our products and offer a 30-day money back guarantee and 90-day in house warranty on refurbished units. Additionally we offer a 30-day money back guarantee on all used products on top of that. Due to the nature of new items, we are unable to accept returns unless there is a technical malfunction and we will be able to replace the unit for you.

We know that exchanging/returning a purchase can be an inconvenience, so we've done our best to create a fair and quick policy to ensure that we can take care of our customers.

We take our customer service very seriously. We work as fast as we can to ensure we process everything quickly. However, we are human, so please allow 24-72 hours for processing after the unit has been received at our office.

In the very rare event that you need to return or exchange your unit, the options available to you are:

Please contact us with as much information regarding your return/exchange as possible.


  • Your Order #
  • Best contact information to reach you at
  • Specific reason for return/exchange (PLEASE read our FAQ's before requesting a return)
  • Which of the below options you would like to take advantage of to ensure we resolve the issue quickly.

No Returns will be accepted without prior authorization.

You may choose 1 of 3 options so we can make sure both parties are satisfied:

(1) Full Refund

You can send the unit back to us and we can refund you in full. We will also then cancel the eBay transaction so neither side is left responsible for the transaction. (Buyer pays return shipping).

(2) Exchange

You can send the unit back and once the unit is received and inspected, we will send a working replacement to you free of charge. (Buyer pays return shipping).

(3) Purchase-Exchange

You can purchase another unit from us so that we may ship it right away, and we will ship a prepaid return label for the original unit. When the unit returns to us we will refund the first transaction in full. (Seller pays return shipping).

It is our mission to ensure that all of our customers get the best product and the best price and are completely satisfied with their experience shopping with us.


Please only ship the calculator (no accessories such as cd, cables, etc…) We recommend shipping via USPS 1st class mail for cheapest service. Most units only will be 8-10oz (and under $3 to ship back). All exchanges will be sent out via USPS 1st Class Mail free of charge as soon as your unit is received.


We must be notified within 14-days of package arrival as stated in our return policy. All returns within 30 days, we will be happy to refund in full. Please send back calculator and all accessories. All refunds will be checked to ensure claims. If item is deemed faulty or defective we will happily refund your entire purchase price including shipping and handling charges you paid for us to ship the item. For eBay purchases specifically, due to PayPal limitations, we are unable to refund return shipping & handling for any transactions and this is the responsibility of the buyer.

If the return is deemed to be properly working and the return is due to user purchasing wrong item or misuse we must charge a 10% re-stocking fee to cover our costs to ship, inspect, and put the unit back into inventory.

We try to make this process as smooth as possible, and we appreciate your cooperation.