Yes. If you don't want to pay 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 will remain open and you can continue to list items on Amazon as an Individual seller, but you will lose access to Professional plan benefits such as uploading in bulk, order reports, customised delivery rates for selling partners or special listing features. Also, remember that only Professional plan selling partner listings can be the featured offer on product pages.