If you're used to dialing your travel agent, credit card company or other businesses toll-free from the United States, it might come as a shock to realize that you can't always access those free calls from other countries, even close neighbors like Mexico. That said, there are a few workarounds you can use to get that call through – although it won't always be free.

Dial an International Exit Code

In a few limited cases, businesses may accept international forwarding of toll-free calls or invest in a Universal International Freephone Number – basically, a toll-free number that works in many countries around the world. In that case, all you have to do is dial the international exit code for Mexico – 00 – followed by the toll-free prefix and the seven-digit number. Be warned that you might still end up paying fees for placing an international call, toll-free number or not, so check the fine print at your hotel or with your cellphone company to be sure – or brace yourself for a possible surprise on your next bill.

Check the Company Website

Airlines, big hotel chains or other companies that do lots of international business might have a number for international access or even a toll-free number that's specific to Mexico. Check the company website for that listing or, even better, call the company before your trip to collect any access numbers you'll need while on the road. The call might not be toll-free, but at least it'll go through. Some companies will even tell you to call them collect during international travel.

Substitute Phone Codes

You can dial almost any U.S. toll-free number from Mexico simply by changing the digits in the toll-free prefix. There's just one catch: The call is no longer free. But, again, at least it goes through – and if you're dealing with a lost credit or debit card or frantically trying to reschedule your cruise, that makes all the difference in the world. Here are the substitutions you must make:

  • Replace 1-800 with 001-880.
  • Replace 1-888 with 001-881.
  • Replace 1-877 with 001-882.
  • Replace 1-866 with 001-883.
  • Replace 1-855 with 001-884.

So, if you wanted to call 1-800-123-4567 from Mexico, you'd dial 001-880-123-4567.

Place Your Call Online

You can make your call by using a Voice over internet Protocol or VoIP, such as Skype, which lets you place toll-free calls internationally at no extra cost, although you may have to purchase credits with the VoIP itself. Making sure your caller ID function is turned on increases the odds that your call will be accepted.