You usually have to have an authorization on file with them allowing you to do that.
Square most likely has something in place where the customer selects if they want the card saved and recurring charges authorized. You should check with them directly first. If you don't have it, you should reach out to the customer and have them complete an authorization form.
This will help you if the customer wants to claim unauthorized charges down the road.
If you have more Qs, feel free to reach out.
-Lubov Bogopolskaya
A/Z Bookkeeping