One of the positions that I had when I worked in hotels was telephone operator and that is where I learned a little bit about dialing from Mexico, mostly to the US/Canada.
These examples are dialing from Puerto Vallarta
Local Landline: (No area code) only the last 7 digits [example: 222 2222]
Local Cellphone: 044 + (area code) + 7 digits [example: 044 322 222 2222]
National Landline: 01 + (area code) + 7 digits [example: 01 474 777 7777]
National Cellphone: 045 + (area code) + 7 digits [example: 045 474 777 7777]
US/CAN Landline or Cellphone (same dialing) 001 + (area code) + 7 digits [example: 001 480 888 8888]
US/CAN Toll Free - (NOT FREE from Mexico)
800 ( 001 880 + 7 digits)
888 ( 001 881 + 7 digits)
877 ( 001 882 + 7 digits)
866 ( 001 883 + 7 digits)
- Dialing from the US/Canada to a number in Mexico it will depend if the number that you are dialing its a landline or a mobile.
Landline: 011 + 52 + (area code) + 7 digits
Mobile Number: 011 + 52 + 1 + (area code) + 7 digits
- Cheapest way to call US/Canada.- If you are coming to Mexico for a period of time and you want to stay in touch with your family/friends back home I recommend that you purchase a really basic cheap phone from telcel (not sponsored) some of them are as cheap as $300mx pesos (around $16USD) and get what we call "plan ilimitado" which is actually the one that I use, you can put in data starting at $20mx pesos (around $1USD) or up to $500mx pesos (around $26USD) and it can give you from 1 day or up to 1 month of UNLIMITED phonecalls depending on the package that you get. I use the $100mx pesos which gives me 17 days and I can make all the calls that I want local, national, to the US or Canada.
- FREE PHONE CALLS: Another option that its very often used here in Mexico to make FREE phonecalls is an app called "whatsapp" (not sponsored) for whatever reason a lot of people from other countries dont use it, or never heard of it. But its a great option because all you/family/friends need to do is download this app which is totally free and all you need is internet access and you can talk as long as you want, you can videochat, you can send text messages or voice messages.
Source: Yayis Travel Advisor