If you are needing to change over money, make sure and do it early in the day.
The exchange rate for the Quetzal is recalculated daily at the Central Bank in Guatemala City. This happens daily at 3 pm. Therefore starting at about that 
time many banks refuse to change money, since they do not know the “current” exchange rate. It may seem like splitting hairs, but that is the way many banks do it. I have found the best way to avoid it is by making time to go to the bank in the morning to exchange money.
In addition, if you are in a more rural area, or a small town, not all banks handle foreign money. Bring your passport with you to change over money at a bank. (Not needed at a money change house)
When you get your money from the bank in Quetzals always make sure to ask for small bills and One Quetzal coins as getting change for large bills on the street can be a pretty hopeless venture.
Oh, and at the bank you will see security guards loaded up with guns and ammo similar to Rambo… don’t worry about that, it is normal. Don’t take pictures though. Taking photos inside banks or of the bank from the outside can land you in some serious trouble.
Coming into the country the exchange window at the Aurora Airport isn’t the most reliable, especially if you are coming in at night. You can either come in with only dollars and expect to pay a little more on a taxi ride (unless you have prearranged it in dollars) or you can try and buy a few Quetzals at your departure airport. Only get as many as you will need before you can get to a bank or Guatemalan exchange house, as the rate is never as good. If you have extra Quetzals left over and want to sell them at the airport exchange house, be forewarned that they don’t always have dollars.
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