By Michael Chen · Published April 28, 2026 · Updated April 28, 2026 · 8 min read
Faxing to Mexico from the US is straightforward once you know the formula: +52 followed by the 10-digit Mexican number. That applies whether you're sending to Mexico City, Guadalajara, Monterrey, or Cancun — and whether the recipient has a landline or a mobile fax number.
The confusing part used to be the old "+52 1" mobile prefix and the domestic "01" dialing prefix. Both were abolished in 2019. Today, one format covers every Mexican number.
This guide covers the exact format, all major city codes, the cheapest way to send, and three mistakes that cause failed deliveries.
Quick Answer
Format for online fax services: +52 [10-digit number] — for example, +52 55 1234 5678 for Mexico City.
Format for a physical fax machine: 011-52-[10-digit number]
Do NOT add "1" after +52 — that format was dropped in 2019 and will fail.
Mexico's Country Code: +52
Mexico's international dialing code is +52, assigned by the International Telecommunication Union (ITU). It applies to every fax and phone number in the country, from the US-Mexico border towns to the Yucatán Peninsula.
When you use an online fax service like mFax.to, you type the + format — the service handles the rest. When you use a physical fax machine in the US, you first dial 011 (the US international exit code), then 52, then the 10-digit Mexican number.
| Method | Full Dial Sequence | Example (Mexico City) |
|---|---|---|
| Online fax service | +52 + 10 digits | +52 55 1234 5678 |
| Physical fax machine (US) | 011-52- + 10 digits | 011-52-55-1234-5678 |
How to Format a Mexican Fax Number
All Mexican phone and fax numbers are exactly 10 digits. The format is: [area code] + [local number], always totaling 10 digits.
There are two types of area codes in Mexico:
- 2-digit area codes: Used only by Mexico City (55), Guadalajara (33), and Monterrey (81). Their local numbers are 8 digits.
- 3-digit area codes: Used by every other city. Their local numbers are 7 digits.
If you receive a number written as "044 55 1234 5678" or "01 33 4567 8901", strip the "044" or "01" prefix — those were domestic dialing prefixes abolished in 2019. Use just the 10-digit number after the prefix, and add +52 at the front.
Mexico City Fax Numbers
Mexico City numbers look like: +52 55 XXXX XXXX
Note that Mexico City also uses the overlay code 56 for newer numbers in the same metro area. Both work identically.
Mexico City and Area Code Reference Table
The table below covers the fax number format for the most common business destinations in Mexico.
| City | Area Code | Format | Example |
|---|---|---|---|
| Mexico City | 55 (also 56) | +52 55 XXXX XXXX | +52 55 1234 5678 |
| Guadalajara | 33 | +52 33 XXXX XXXX | +52 33 1234 5678 |
| Monterrey | 81 | +52 81 XXXX XXXX | +52 81 1234 5678 |
| Cancun | 998 | +52 998 XXX XXXX | +52 998 123 4567 |
| Tijuana | 664 | +52 664 XXX XXXX | +52 664 123 4567 |
| Puebla | 222 | +52 222 XXX XXXX | +52 222 123 4567 |
| Queretaro | 442 | +52 442 XXX XXXX | +52 442 123 4567 |
| Ciudad Juárez | 656 | +52 656 XXX XXXX | +52 656 123 4567 |
| Mérida | 999 | +52 999 XXX XXXX | +52 999 123 4567 |
| Toluca | 722 | +52 722 XXX XXXX | +52 722 123 4567 |
| Chihuahua | 614 | +52 614 XXX XXXX | +52 614 123 4567 |
| Hermosillo | 662 | +52 662 XXX XXXX | +52 662 123 4567 |
| León | 477 | +52 477 XXX XXXX | +52 477 123 4567 |
| San Luis Potosí | 444 | +52 444 XXX XXXX | +52 444 123 4567 |
| Saltillo | 844 | +52 844 XXX XXXX | +52 844 123 4567 |
| Veracruz | 229 | +52 229 XXX XXXX | +52 229 123 4567 |
| Tampico | 833 | +52 833 XXX XXXX | +52 833 123 4567 |
| Acapulco | 744 | +52 744 XXX XXXX | +52 744 123 4567 |
| Puerto Vallarta | 322 | +52 322 XXX XXXX | +52 322 123 4567 |
| Cabo San Lucas | 624 | +52 624 XXX XXXX | +52 624 123 4567 |
| Playa del Carmen | 984 | +52 984 XXX XXXX | +52 984 123 4567 |
Don't see your city?
Every Mexican area code follows the same rule: the area code + local number always adds up to 10 digits. If you have a number that looks shorter or longer, it's either missing the area code or written in an old format that needs updating.
The +52 1 Mobile Mistake (And How Mexico Fixed It)
Before August 3, 2019, Mexican mobile numbers had an extra "1" in the international format: +52 1 [10-digit number]. Landlines were just +52 [10-digit number]. Senders had to know whether the destination was a cell phone or a landline — which caused constant errors.
Mexico's Federal Telecommunications Institute (IFT) eliminated that distinction. Today, every number — landline or mobile — uses exactly the same format: +52 + 10 digits.
If you're using a contact's old business card or a number that says "+52 1…", remove the "1" and dial the remaining 10 digits after +52. The old format either fails entirely or connects to the wrong number.
Similarly, if a Mexican contact gives you a number starting with "01" (the old domestic long-distance prefix) or "044/045" (old cell phone prefixes), strip those digits and use just the 10-digit national number.
Watch Out for Old Formats
Old (incorrect today): +52 1 55 1234 5678 — used for Mexico mobile numbers before 2019
Current (correct): +52 55 1234 5678 — same format for all numbers since August 2019
How to Send a Fax to Mexico Using mFax
mFax.to uses the standard +52 format automatically — no special settings needed for Mexico. You send a fax to Mexico the same way you'd send any international fax.
Open mFax and start a new fax
Download the mFax app or visit mFax.to on your browser. Tap the compose button to start a new fax.
Enter the Mexican fax number in +52 format
In the recipient field, type the number starting with +52, then the 10-digit Mexican number — for example: +52 33 1234 5678 for Guadalajara. Do not use dashes or spaces; mFax formats the number automatically.
Upload your document
Attach your PDF, or use the phone camera to scan a paper document. mFax converts images to a fax-ready format automatically. Need to combine multiple pages first? Use the free Merge PDF tool.
Add a cover sheet (optional)
For business faxes, a cover sheet signals professionalism. Generate one instantly at the free mFax cover sheet generator — no signup required.
Send and track delivery
Tap Send. mFax delivers a confirmation receipt when the fax is successfully received. If delivery fails, the error message tells you exactly why — wrong number format is the most common cause.
What Does It Cost to Fax to Mexico?
Mexico is one of the most affordable international fax destinations from the US, largely because of the deep US-Mexico telecommunications infrastructure built up over decades of trade — the two countries exchange roughly $935 billion in goods and services annually.
| Method | First Page | Each Additional Page | Notes |
|---|---|---|---|
| mFax.to / SRFax | ~$0.05 | ~$0.05 | Same as domestic US rate |
| eFax | $0.20–$0.50 | $0.20–$0.50 | Dynamic pricing; check rate tool |
| FedEx Office (in-store) | $5.99 | $3.99 | International flat rate |
| Staples (in-store) | $5.99 | $3.99 | International flat rate |
| Traditional fax machine | ~$1.79–$2.99/min | — | Carrier international rate per minute |
For anyone faxing to Mexico more than once, an online service pays for itself on the very first page. A five-page fax costs roughly $0.25 online versus $21.95 at a retail store.
See our complete international fax rates guide for a full breakdown by country and service.
Mexico Time Zones: When to Send
Mexico abolished Daylight Saving Time nationally in October 2022. That makes scheduling cross-border faxes simpler — but there are still four time zones to be aware of.
| Region | UTC Offset | DST? | Major Cities | US Equivalent |
|---|---|---|---|---|
| Central (most of country) | UTC−6 | No | Mexico City, Guadalajara, Monterrey, Puebla | US Central Standard Time |
| Pacific | UTC−7 | No | Mazatlán, Sinaloa, Sonora | US Mountain Standard Time |
| Northwest (Baja California) | UTC−8 | Yes | Tijuana, Mexicali, Ensenada | US Pacific Time |
| Southeast | UTC−5 | No | Cancun, Playa del Carmen | US Eastern Standard Time |
Key timing facts:
- Mexico City and most of Mexico stay at UTC−6 year-round. During US Daylight Saving (March–November), Mexico City is 1 hour behind US Central time.
- Tijuana still observes DST to stay synchronized with San Diego and California.
- Cancun is permanently on Eastern Standard Time (UTC−5) — the same as New York during winter months.
The safest faxing window: 9 AM–4 PM local time at the destination. For Mexico City, that means sending between 10 AM and 5 PM Eastern, or 9 AM–4 PM Central.
Why So Many US Businesses Fax to Mexico
The US and Mexico are deeply integrated trading partners. Mexico is the #1 source of US imports as of 2025, supplying everything from automotive components to medical devices to fresh produce. The USMCA (which replaced NAFTA in 2020) further deepened cross-border business ties.
Industries that regularly fax to Mexico include:
- Manufacturing and automotive: Legal compliance documents, purchase orders, supplier agreements between US companies and their Mexican counterparts
- Healthcare: Patient records, insurance claims, COFEPRIS regulatory filings, and prescription authorizations near the US-Mexico border
- Legal and real estate: Notarized documents, cross-border property transactions, and maquiladora operating agreements
- Agriculture: Phytosanitary certificates, import permits, and commodity purchase orders for the $48B+ in Mexican agricultural exports to the US
- Customs and logistics: Import/export declarations and customs broker communications along major border crossings
For compliance-heavy industries, see how mFax Business handles secure, auditable fax delivery with delivery confirmation logs.
Common Mistakes When Faxing to Mexico
1. Using the old +52 1 mobile format. This was dropped in 2019. Remove the "1" and dial +52 followed directly by the 10-digit number.
2. Including domestic prefixes. If someone gives you a number starting with 01, 044, or 045 — strip those and use just the 10-digit national number with +52 in front.
3. Using 011-52 with an online fax service. The 011 exit code is for physical fax machines only. Online services like mFax expect the + format: +52, not 011-52.
4. Wrong digit count. Every Mexican number is exactly 10 digits after the +52. If you're counting 11 or 9, something is wrong — either a stray "1" was left in, or a digit was dropped.
5. Confusing area code lengths. Only Mexico City (55/56), Guadalajara (33), and Monterrey (81) have 2-digit area codes. If you see a 3-digit area code followed by what looks like 8 digits, the number is incorrect — it should be a 3-digit code + 7 local digits.
For a broader look at international fax formats, see our complete list of fax country codes.
Conclusion
To fax to Mexico from the US, use this format with any online service:
+52 [10-digit Mexican number]
That's true for every city, every carrier, and every number type — landline or mobile — since Mexico unified its numbering in 2019. Mexico City numbers start with 55, Guadalajara with 33, Monterrey with 81, and everything else uses a 3-digit area code.
mFax.to makes it simple: enter the +52 number, upload your document, and send. Delivery confirmation arrives in minutes, and the cost is the same as a domestic fax.
Send your first fax to Mexico — download the mFax app or start at mFax.to. No machine, no store trip, no per-minute phone charges.