ChatGPT offers a permanent Free plan with basic access for all users....

https://sierra-wiki.win/index.php/If_My_Trial_Needs_a_Card,_Will_It_Charge_Exactly_on_the_End_Date%3F

ChatGPT offers a permanent Free plan with basic access for all users. Occasionally, targeted promotions provide free trials for the Plus plan, which may require a card and auto-renew into a paid subscription when the trial ends