Hotels/ATM debit card

Cash is preferred. Many hotels in Germany do not accept credit cards, so they would also not accept debit or travel cards.

Small hotels often do not take credit cards, but most any mid-sized and larger hotel will take credit cards. I've never stayed at a place that only accepts cash. Technically, if they take credit cards, a debit card should work. BUT.... It is VERY unwise to use a debit card for purchases in Europe. Account theft does happen, and if someone steals your card info, they will wipe out your checking account until the issue is resolved. That leaves you without any access to cash and may cause significant problems with automatic withdrawls while you are gone. It's a hassle when at home; it can be paralyzing when traveling abroad. By "travel" card, do you mean something like a Travelex pre-paid card? Keep in mind those have very high fees and/or very poor exchange rates. They can be of value in some cases, but paying for hotels is not one of them. Any reason you don't want to use a credit card?

Another issue with using debit cards at a hotel, is that a hold can be placed on the funds in your checking account when you check-in. When you check-out the bill will be deducted from your account be the original hold may not be released right away; it could take a few days. This may cause some temporary cash flow problems. When you use a regular credit card the hold is placed on your credit limit. Same deal with rental cars.......

According to a pension owner I talked to on my last trip, credit card companies get a 10% cut of the total, so he doesn't take them (nor does he use booking websites, which get 15%). In Germany, I generally stay in smaller places that don't take credit cards, and I average about €30/night, single occupancy with breakfast. I find that places that do take credit cards already charge more than is necessary or I want to pay.

Hotel? Big, Medium, Small, chain? or B&B? We are going to Frankfurt in August and will pay cash at a place to get a discount that was offered. In going to Europe every summer, I have never not paid cash at a B&B. If in a hotel, sometimes a CC if acceptable or cash if a discount is offered.

As said, it depends on the hotel. You have to check with each one. I agree that paying with a debit card exposes you to potential problems, for the reasons stated above. I don't like using my credit card because it has higher fees than my ATM card. So, I pay with cash, withdrawn from an ATM and stored in my moneybelt. If the issue is that your credit card has high fees, do note that you can get ones that don't (Capital One and credit unions are two common sources of cards with low or no fees for foreign transactions). I'm just too lazy to get these - but that doesn't have to stop you. Everything else you need to know about money abroad is here: http://www.ricksteves.com/plan/tips/money-travel-tips.htm