Thank you for reaching out to the Community about your sign-up forms! I apologize there are times were contacts are getting added to lists they should not be. This is something we would like to take a further look into. Because it sounds like you're working with a custom API, I suggest reaching out to our API Support team . These developers and support agents can be reached by email at webservices(at)constantcontact(dot)com. Please let us know if there is anything else we can assist with.
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