We only sell custom made blinds that are made to the size of your window. They cannot be returned or exchanged except if they are a subject of warranty claim. Once your blinds enter production they cannot be cancelled or modified. If you follow our How to Measure instructions we guarantee that your blinds will fit your windows perfectly. Sometimes mistakes can happen and if we make a mistake we will either repair or replace the blind that is the subject of a claim at no cost to you. If it happens that you have made a mistake while ordering or measuring, please contact us and we will try to help you. Depending on the type of error, the blind(s) may be altered or we could have it remade for you at a discount price.