My girlfriend & I would like to open a joint checking/debit account. However, my credit is less than perfect & hers is very good. She's worried that my rating will bring her rating down.

Will this affect her rating?
This account will not be a primary account for either of us; it's mainly going to be used for shared things (dinner, movies, things for the house, etc.). We're both planning on depositing equal funds periodically.

Having a checking account does not effect your credit. Checking accounts are linked to a seperate system called Chex Systems. If you have a bad history of overdrawing or charging off the account, then you get reported to Chex and all financial institutions use this for determining whether or not the can open/add you to a checking account.

Your credit can not be effected unless you have a debt on the checking account that hasn't been paid and they report you to collections, which banks typically don't do because they just sell the debt.

The people who said yes clearly don't know what they are talking about.

YES DEFINITELY, I OPENED A JOINT ACCOUNT BEFORE I MARRIED MY HUSBAND AND DIDN'T KNOW WHAT WAS GOING ON WITH HIS FINANCES, SO BE CAREFUL..

YES DEFINITELY, I OPENED A JOINT ACCOUNT BEFORE I MARRIED MY HUSBAND AND DIDN'T KNOW WHAT WAS GOING ON WITH HIS FINANCES, SO BE CAREFUL..