Do I even need credit cards?
Eventually you are going to need some sort of real credit history.  It is possible that you will be able to evade this if you never buy a house, or if you pay cash for any house/condo/car/boat/etc that you buy.  Even employers check credit history these days.  I wouldn't be surprised if some medical professionals such as surgeons check it also.  Obviously if you have a mortgage and car loan this doesn't apply, but I'd be curious how you acquired those unless you have substantial income and/or assets. Combine this with the fact that certain things like renting a car essentially require a credit card (because they need to put a hold on more money than they are actually going to take out of your card, so they can take that money if you don't bring the car back), and I think you should have a credit card unless you and your wife are individuals with zero impulse control, which sounds highly improbable. If your concern is the financial liability of the credit line, just keep the credit line low.