Do you have to take the writing portion everytime?

<p>I have been informed by multiple people that I MUST take the writing on every ACT retake or I cannot send in my scores for that test. Is this true? I took the writing portion in April and figured you only had to take it once so I signed up for just the the test in September. Will colleges let me send in my old writing score? If not, then am I just wasting my time going Saturday?</p>