How old do you have to be to have your ears pierced at a piercing parlor?

I don’t want to go to piercing pagoda or Claire’s or anything. I want it done at a needle. There are a few piecing/tattoo places nearby but I was wondering if age requirements are common. My kids are 4 and 5 and want their ears pierced. Will they be able to get it done? Does it vary by shop or do they just do it for whoever walks in as long as a parent is there? Thanks in advance.

I know I can call and ask. I’m wondering if anyone has experience or has maybe worked in one. I want to know if it’s typical or not.