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 ATM card with a different bank. I had some clients who both had called their bank and were given the OK. Unfortunately, during our week there, neither of them were able to use their card. 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. Without calling, most credit card companies will see charges thousands of miles away from your usual use pattern and shut you down
As with the ATM card, bring more than one credit card with you if possible. If for some reason one card doesn't work, you have another. The second card is also useful if you have an emergency.
DOCUMENT BANK AND CREDIT CARD INFORMATION
Be sure that you have the information you need in case your card is stolen. Do not keep it in your purse of wallet and be sure to 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.
Monitor your accounts, just in case.
CHANGE SOME MONEY BEFORE YOU LEAVE
There's nothing more annoying than arriving at the airport at 6:30 in the morning with no cash for a bite to eat, cup of coffee, or to pay for a taxi or shuttle. If you rent an apartment, you might need to pay the balance and security deposit when you arrive.
ATMs have a maximum dollar amount you can withdraw each day. Check with your bank before leaving.
Money exchangers are expensive.Instead, call your bank. They may require a lead time to get the Euros, so don't leave this task until the last minute.
BRING A CHANGE PURSE
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.