For friends, family, and business contacts, contacting a person on a satellite phone can be a bit of a headache. (See a popular blog post we did about the cost of calling a satellite phone from your US cellphone). This is because satphones (with the exception of Globalstar) are have special International phone numbers that - if your carrier doesn't block them outright - can be incredibly expensive to call.
So what about SMS? Sending a SMS to a satphone is actually much easier to do than making a voice call, SMS rates to satellite phone numbers can still be much pricier than texting other cellphones. For that reason, most of the satellite carriers have ways to send a SMS to a satellite phone for free.
Inmarsat, Iridium, Thuraya, and Globalstar SMS
To send a SMS to an Inmarsat satellite phone you can use their online web form or you can send an email in the following format: 87077642xxxx@message.inmarsat.com (the first part of the email address is the satellite phone number).
To send a SMS to an Iridium satellite phone, you can use their online web form here, or you can send an email in the following format: 8816XXXXXXXX@msg.iridium.com (the first part of the email address is the satellite phone number).
To send a SMS to a Thuraya phone number, you can use their online web form here, or you can send an email in the following format: 88216xxxxxxxx@sms.thuraya.com (the first part of the email address is the satellite phone number).
To send a SMS to a Globalstar phone number, you can use your cellphone, since Globalstar uses US-based phone numbers for its satellite phone users. Note that Globalstar SMS messages to Globastar satellite phones are limited to 17 characters instead of 160, so keep it (very!) short!*
*Globalstar Sat-Fi supports full SMS messages.
Cost of Sending SMS to Satellite Phone
If you're going to send an SMS message directly from your cellphone to a satellite phone, you will typically pay between $0.25 to $0.50 per message (Verizon looks to be an exception). We did some investigative reporting to figure out exactly what you would pay with some of the most popular carriers:
T-Mobile: $0.50 per SMS
AT&T: Unable to verify specifically for satellite phones, but looks to be either $0.25 or $0.50 for a SMS message.
Verizon: According to the Verizon rep I spoke with, all SMS messages, even to satellite phones, are free with any Verizon plan.
Sprint: Customer support or sales wouldn't release plan information without proof of a valid Sprint phone number, so we were unable to verify costs for sending an SMS to a satellite phone using a Sprint cellphone.
What Is The Cheapest Way to Contact A Satellite Phone From Land?
If you send an SMS via email or using one of the webforms linked to above, the SMS is free for you and the satellite phone user, so this is an inexpensive way to get in contact with those on satellite phones.
The downsides of SMS use with satellite phones are that it's usually difficult to send SMS on the satellite phone itself (so responding to your text message can be difficult), sending SMS on a satellite phone is typically pretty pricey, and you're restricted to a very short message (in Globastar's case, an extremely short message). For longer communication, we would definitely recommend XGate email for satellite phone users.
Further Reading
Not sure which satellite phone or system is right for you? We want to help you understand the complicated world of satellite equipment so that you can make the best choice for your needs. Here are a few free resources you can use to learn about satellite communications.
Free Guide to Affordable Satellite Broadband Internet
Free Guide to Blue Water Cruising Communications
Free Satellite Communications Consultation