We use credit cards so often they sometimes feel the same as cash – but unfortunately, that couldn’t be further from the truth.

When you use a credit card, you’re taking out a loan from a financial institution. Every time you swipe, you’re asking for authorization to spend money that’s not really yours. In fact, there are some purchases for which card issuers won’t lend money. Check out these five things you can’t pay for with credit cards:

1. Gambling

If you’re in the mood to take chances, you’ll probably have to use cold, hard cash. State laws and casino policies often forbid the use of credit cards, and if not, card issuers themselves sometimes refuse to cover such high-risk spending. While these lenders profit from the interest you accrue when carrying a balance, they don’t want you to get carried away and run up charges you can’t afford to pay back.

2. Semi-Legal Products

Credit-card issuers also remain skeptical of the newly emerging retail-marijuana marketplace, especially since state and federal laws contradict each other in some areas. For the moment, lenders seem to prefer remaining outside the legal scramble. Likewise, you may have trouble using credit cards to pay for online pornography, because some sectors of that marketplace involve potentially criminal activity.

3. Mortgages

Even if your credit card comes with a high limit, you can’t pay your mortgage with it. Mortgage lenders won’t encourage buyers to pay off debt by accumulating more debt at higher interest rates. The possibility of future default is too high.

4. Student Loans

You probably won’t be able to use credit cards to pay your student loans. Policies regarding these loans vary between lenders, though, and may depend on your personal situation (i.e. type of student loans you borrowed).

5. Automobiles

You generally can’t use credit cards to buy a car, either – although once you have your auto loan, you may be able to do a balance transfer. This would only benefit you if you take advantage of a zero-interest offer on a credit card and pay off the balance before interest kicks in.

Credit Cards Are Only Part of Your Financial Picture

The fact your credit cards can’t cover every possible expense is a good reminder there’s still a place for cash in your pocket, as well as for lower-interest forms of borrowing. The best money management includes a flexible blend of all forms of payment.