No sales tax for US and else where excluding Colorado residents:

Exchanges. We'll happily make exchanges for defective merchandise of equal or lesser value. All items must be returned in their original packaging, unused. Note: certain custom-made items (crates, beds, most cat furniture are not returnable or exchangeable).

Shipping Charges. We pay shipping charges on the return of items due to manufacturing defect only. For all other returns, credit will be given for the item only, not the shipping charges. Unless the return is for a defective product, you are required to pay all shipping charges.