Yes. If you don’t want to be charged a monthly subscription fee, you can downgrade your account from the Professional plan to the Individual plan from the My Services page
in Seller Central (login required).
If you downgrade, your account stays open and you can keep offering items on Amazon as an Individual selling partner, but you’ll lose access to Professional plan benefits like bulk upload, order reports, selling partner-customized shipping rates, or special listing features. Also, keep in mind that only offers from Professional Selling Partners are eligible for featured offer status on product detail pages.