Hi, bella, welcome to the forums!
Piggybacking does mean adding on as an AU (authorized user), and then presumably dropping back off when no longer needed.
Those who buy and sell strangers' credit in this manner have caused a change in scoring where eventually AU accounts will not help scores. But there are still plenty of family members who do this. I'm an AU on one of my husband's cards.
There is a difference between AU and joint. AU simply means that you can use the card, with limited or no responsibility for paying the bills. Joint means that two people are co-owners of the account, equally responsible for the balance, whether they knew what the other person was doing or not. A joint owner cannot remove himself/herself from the account --they're stuck for good.
If you wanted to go on one or two of your husband's cards as an AU, that could help your scores for the time being. The best account is one that has been open for a long time, has never, ever had a late payment, and has a $0 balance reporting, or a very low balance. I personally feel that if someone is going AU on a spouse's card for this reason, the card shouldn't be used. My AU card is in a dresser drawer, and I don't consider it mine. So this is something that you should think through with your husband.
And by the way, it would be wise not to use the term "piggybacking" on the forums, as most people associate it with the unethical use of stranger's credit for a price.
This particular thread is a very old one.
It would help you to read Credit Scoring 101, or at least the first post. (It's an incredibly long thread these days!) You'll find it stickied up at the top of this board and on several others as well. There's a lot more to fixing up your credit than trying to get some help from an AU account, and Credit Scoring 101 will help you start. Good luck!
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007