I am new in this. If we have to file an amended CTR. Do we complete the entire CTR again and mark Amends Prior Report or just complete the part that has to be corected. Thanks for your help.

If I am not mistaken it tells you in the computer generated facsimile to not send a new form. I think you are suppose to use the form they provide to correct your answers/ommissions. If you do a new form, I think you may confuse the folks at the IRS into thinking it is a new CTR, but I am not sure as to the reason!

From CTR Instructions:
Item 1a. Amends Prior Report. If this CTR is being filed because it amends a report filed previously, check Item 1a. Staple a copy of the original CTR to the amended one, complete Part III fully and only those other entries which are being amended.