Thank you for reaching out to Constant Contact's API Support.
The company field is one of our default fields on a contact profile and the name of that field cannot be changed.
If you are using the sign-up form that is provided with the Constant Contact account then you can use a custom field and name it Organization to collect that data. You can also do this to mimic a message field, but please keep in mind the maximum character limit for that field through the sign-up form is 50 characters.
Regards, Jimmy D. Tier II API Support Engineer
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