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GTC Airtime Knowledge & Support Hub
Discover how GTC satellite airtime packages work, the difference between prepaid and monthly plans, and how to choose the right service for your device.
What is Satellite Airtime?
Airtime is the satellite network service that allows a satellite device to communicate. Whether you are using a satellite phone, GPS tracker, satellite messenger, or broadband terminal, airtime is what enables the device to send and receive data across the satellite network.
Unlike traditional mobile services, satellite airtime plans are tied to specific satellite networks such as Iridium, Inmarsat, Globalstar, Thuraya, and Starlink. Each network has its own coverage footprint, pricing structure, and service capabilities.
Depending on the device and how often it is used, airtime can either be purchased as prepaid top-ups or through a recurring monthly contract. Some users only need occasional access for emergency backup or expeditions, while others require continuous connectivity for business operations, vessels, remote sites, or permanently deployed equipment.
Choosing the right airtime setup is often about balancing flexibility, ongoing costs, coverage requirements, and expected usage.
NB: airtime results are already pre-filtered
Prepaid vs. Postpaid Airtime
Our satellite airtime solutions fall into two categories: prepaid airtime SIMs or top-up vouchers, and postpaid monthly contracts. Both provide access to the satellite network, but they are designed for different usage patterns.
Prepaid Airtime
Flexible Pay-As-You-Go Access
Prepaid satellite airtime works similarly to a mobile phone top-up. You purchase a bundle of units, minutes, messages, or data that remains active for a fixed validity period.
This option is popular with users who only need satellite communications occasionally, such as hikers, expeditions, emergency backup users, seasonal workers, and short-term deployments.
Typical Benefits
- No monthly billing
- Flexible short-term use
- Good for emergency backup devices
- Easier to control spending
- Simple top-up structure
Common Uses
- Adventure travel
- Emergency preparedness
- Rental devices
- Temporary remote work
- Seasonal marine usage
Postpaid Airtime
Ongoing Monthly Service Plans
Postpaid airtime operates on a recurring monthly contract. Instead of topping up manually, the service remains continuously active with monthly billing.
This approach is usually preferred for business operations, vessels, lone worker dute of care, permanently installed equipment, and users who rely on satellite connectivity for longer-term operations.
Typical Benefits
- Always-active service
- Predictable monthly billing
- Better for frequent usage
- Suitable for permanent deployments
- Often lower usage costs over time
Common Uses
- Commercial marine operations
- Fleet tracking
- Remote infrastructure
- Business continuity
- Remote workforce communications
Satellite Network Coverages
Different satellite networks are designed for different types of communication, coverage areas, and applications. Understanding the strengths of each network can help narrow down the right airtime solution.
Iridium
Iridium offers truly global coverage, including oceans and polar regions. It is widely used for handheld satellite phones, tracking devices, and emergency communications.
Inmarsat
Inmarsat provides near-global coverage and is commonly used for maritime communications, fixed-site broadband, and professional satellite voice services.
Thuraya
Thuraya focuses on regional coverage across Europe, Africa, the Middle East, Asia, and Australia, offering satellite voice and broadband services for users operating within those regions.
Globalstar
Globalstar is often used for satellite messengers, tracking systems, and SPOT devices. It is popular for personal safety, asset tracking, and lightweight communications.
Globalstar (prepaid)
Flexible prepaid airtime for compatible Globalstar satellite phones and devices, designed for occasional use, emergency backup, travel, and remote communications within the Globalstar coverage footprint.
SPOT & Simplex
Satellite messaging and tracking coverage for SPOT devices and simplex tracking applications, supporting SOS alerts, GPS tracking, and remote asset monitoring beyond cellular coverage.
Frequently Asked Questions
For a prepaid airtime customer, you are required to go to our activation page once you have received the SIM card. For pay monthly airtime customers, you are asked to input an activation date on the airtime contract so we can set up activation as part of contract processing.
Yes, you will receive an automatic email including balance and expiration date shortly before airtime expires. Check with us that your email address has been registered for updates. Upon request we can also send an SMS message to satellite phones. You can also manually check your balance at any time on the device.
Generally call rates are the same unless you choose specific SIM options or vouchers. For example, a Thuraya NOVA SIM offers customers inside the NOVA zones lower rates than a standard Thuraya SIM. Similarly, an Iridium regional voucher gives preferential rates in certain countries.
Airtime validity depends on the network and plan. For example, one of our Iridium top-up vouchers has a 730-day validity period, while our Inmarsat top-up vouchers range from 30 to 90 days' validity. However, all of this information is detailed on our airtime pages and confirmed during purchase. We also send reminder emails when your airtime is nearing expiry.
Yes. Calling a satellite device can be expensive due to terrestrial network charges. We recommend arranging a call time via message and having the satellite phone user place the call. SMS and two-way messaging via satellite communicator is usually far cheaper,
Unfortunately not. Even SOS functions require airtime (data or SMS) to send alerts. Running out of airtime can be dangerous in remote areas. Always check your balance and respond to low-balance notifications.