Error notes are banknotes that spot mistakes made during printing or production. These can include things like misaligned images, smudged ink, wrong or missing serial numbers, or notes that were cut the wrong way. Some error notes look visibly different—when they are “major errors”. Some look fairly normal—when they are”minor errors”. But all, including the ones that look different, are legal tender and can be used like normal notes. Because the printing process is usually very careful, most error notes are removed and replaced by replacement notes before they reach the public. So when an error note does make it into circulation—especially one with a major error—it is rare and many collectors find it valuable. There are three main types of error notes: serial number errors, printing errors, and cutting errors.