As is tradition in the family, upon graduation from high school you are give n a credit card, a master card...Now the other day my mom said that in one family you can only have up to 4 credit cards registered under one family. Does anyone know if thats true?

I assume that you are speaking of authorized users on your parents accounts.

Each credit company sets its own limits for the number of cards it will allow per each account.

So very likely you mom is telling the truth.

Yes 4 Credit cards registered to one account.
You can have as many credit cards account as you want.
Just make sure you can pay at the end of the month.

I can have as many as I need. Different cards have different rules.

She may only be able to order four cards for one account. That sounds right.

you can actually have unlimited credit cards if your credit is good, it all depends if you get approved or NOT