You don't have to, and it is IMO, a bad thing to fill out a reseller agreement form unless a retail store.
That allows government and needless distractions to track you all the time and make excuses to attack you, I've seen the horror stories of that garbage. Thankfully its all dying away now.
But I just don't agree with reseller forms. I was offered this job by somebody in the U.K. offering me a bunch of money and an agreement form to sell items for him, I turned it down.
I'm independent and I'm not interested in anyone putting anymore restrictions, control, or faulty ideas over me than I already deal with. The Postal office is enough and there is a lawyer who always gives out the most expert advice.
I crossed my Ts and Qs and dotted them everywhere. If you can help it, go independent. Don't become an authorized reseller or fill out forms given to the government or governmental affairs unless regulations of your product leave no alternative.