by John Burnett:
First, let's remember that when the dollar amount in figures is not the same as the dollar amount in words on a check that states the amount twice (checks do not HAVE to include the dollar amount both in figures and words), the amount in words controls. UCC §3-114, Contradictory Terms of Instrument.
Adding an annotation to show that you have taken the amount in words instead of the amount in figures is permitted, since it does not alter the original terms of the check.
by Brian Crow:
Legally, John’s answer is correct. Operationally, technology has changed over the years. Depending on any check imaging software that your institution utilizes, it may only detect blue or black ink and those whom you want to see the notation may not be able to read it.