The availability of banks and ATMs on Holbox has improved to some degree since 2006 but they are still few and far between. There is only one official bank operated ATM on the island; Bancomer located on Av. Díaz just off the square and it frequently runs out of pesos. There are other ATMs scattered around but some only give out U.S. Dollars and all charge a very high service fee.
Most businesses will accept U.S. Dollars (and some will take Euros) but you have to pay attention to the exchange rate.
Most tourist hotels will also change money for guests but typically at a less than official rate.
Virtually all merchants, hotels and restaurants that cater to tourist will accept credit cards but will likely add up to a 5% premium for bank processing. (Not everyone takes advantage but) you’re also subject to exchange rate games on credit cards as well. One trick is a price quoted in dollars will be based on the original price in pesos adjusted by a rate more favorable to the merchant than the customer. But when you receive your credit card bill, your bank will have converted back using a close to real rate, which will result in an inflated charge to your card.
So our advice is to find a bank machine or money changer before you travel to Holbox and carry an ample supply of pesos with you when you arrive on the island.
You should also bring an ample supply of insect repellent as mosquitos can be fierce at times.
All the streets in Holbox are sand, which over time in even the best of circumstances will develop potholes. Add underground natural water springs, which are common on the island to the mix and the result is perpetual DEEP mud holes on some of the main routes in town making driving or even walking down some blocks extremely challenging.