I get a lot of questions about how to deal with money while traveling in Paris, and France in general.
If you do the preliminary preparation, it should be a non-issue.
DON'T BRING TRAVELERS CHECKS
Traveler's Checks used to be the standard for travel. Now, they are not readily accepted in France. If someone does accept them, they may not give you the best exchange rate if the Traveler's Checks are in anything but Euro.
USE YOUR ATM CARD
Your ATM card will be your best friend (well, maybe next to your credit card.) ATM machines are plentiful in Paris and will give you the best exchange rate on that day.
Be sure to check with your bank before you go to be sure it will work in France.
If possible, bring a second one with a different bank. I had some clients who both had called their bank and were prepared to use their ATM card in Paris. Unfortunately, during our week there, neither of them were able to use it. Getting cash from your credit card is very expensive.
In order to stay on budget, minimize fees and be sure I have enough cash for the spontaneous nature of a day in Paris, I take out 2-3 days worth of cash at a time. When it's gone, it's gone. When that happens, it's time to relax and enjoy the free things Paris has to offer and to create a nice meal in my apartment kitchen!
CALL YOUR CREDIT CARD COMPANIES
Check with your credit card company about what you need to do to assure successful charging in Paris. Each company is different. Mine, for instance, was automated and had to be done within two days of using it in France. But your's may be different. Without calling, most credit card companies will see charges thousands of miles away from your usual use pattern and shut you down. In my earlier years, that happened to my husband and I. Fortunately, we had two cards and the other company wasn't so protective.
As with the ATM card, I suggest that you bring more than one credit card with you if possible. The reason is the same - if for some reason one card doesn't work, you have another (see above). The second card is also useful if you have an emergency. Hopefully you have, at the very least, purchased catastrophic insurance coverage for your trip. But even then, you may find cash (or credit) is still King.
DOCUMENT BANKING INFORMATION
Be sure that you have written the information for your accounts so that if you have a stolen card, you can call the appropriate numbers quickly. Be sure, however, that you NEVER write down your passwords. Keeping this information securely in "the cloud" in an email attachment or something is another possibility but may not be as convenient.
CHANGE SOME MONEY BEFORE YOU LEAVE
There's nothing more annoying than arriving at Charles de Gaulle airport at 6:30 in the morning and have no cash for a bite to eat, cup of coffee, or to pay for a taxi or shuttle. There are plenty of places at Charles de Gaulle to exchange your money but Murphy's Law will make sure you that if you need to find them, they will not be obvious (however, you'll see ten exchange booths while you wait to go home!)
There are also places to change money at the airport before you leave the States. Be warned, their fees will not be in your favor.
You can call your bank. They may require a lead time to get the Euros that you need, so don't leave this task until the last minute.
Bring A Change Purse
This may sound strange, but Europeans use coins much more than Americans. It's important to have change for small purchases, public transport (if you don't have a pass,) and the WC. Chances are, you'll have many more coins than you have paper money.
#8 At the Airport
My favorite currency conversion site: