There is a lot of difference between notes that have been altered and those that have been repaired. There are several questions, pertaining to the issue of altered notes compared to repaired notes. A note that has been repaired is simply enhanced to improve the note’s condition. On the other hand, altered notes are notes that have been worked on to give the appearance of another note.
For example, many US Small Size notes have been altered to give the appearance of errors. We have seen dot matrix examples of printings on top of original notes in an effort to create double print errors, offset printing errors, inking errors, etc. We have also seen US notes that have been cut from BEP issued sheets incorrectly to give the appearance of a misalignment error. The notes are considered altered because the cutting did not occur during the issuing process.
Altering is very common in other parts of the world as well as the US. There are several Chinese notes altered to create the appearance of specimens. The original serial number on these notes is removed from the surface and replaced with the 000000 serial number that is used on specimens. Also, these notes have false overprints that are used to create the appearance of a specimen or other variety. However, there several good alteration examples, so it is important to closely examine all notes. We have also seen notes with cancel holes that have been filled in to give the appearance of an issued note that had not been canceled. Some notes are much rarer in this form, so it is easy to see why altering occurs.
Repaired notes are notes that have been worked on to improve their appearance. If there is a note that is discoloured, a substance is added to the surface to repair the stained area.
Tears, splits, ink burn, etc. are often repaired with some type of adhesive to close the area and improve the overall appearance. Also, many repairs are done to increase the value of the note. But, if a cancel hole is filled with something to create the appearance of a non-cancelled note, then it is not a repair. This is a form of altering the note rather than repairing the note. If a tear coming off a cancel hole is closed, but the hole remains open, the note has been repaired rather than altered.