Blog de LabsMobile noticias y novedades

Gray routes and direct SMS routes

In the digital age, businesses have adopted various communication strategies, with SMS marketing being one of the most effective. However, choosing the right SMS sending routes is crucial for the success of a campaign. Among these routes, grey routes stand out for their low cost, though they come with several risks.

9 minutes of reading
Publication: 07.08.2024
Última modificación: 07.17.2024

Planning an SMS strategy involves a financial investment that businesses must face. Remember that the volume of SMS sent is high, and with it, the cost, but that will depend on the route chosen to send mass messages to mobiles.

Today, different routes can be found, of varying quality, and, of course, the lower the quality, the cheaper it will be (and so will its effectiveness).

SMS Connection Routes

SMS connection routes are the paths that messages travel from a platform to the recipient's device. There are two main types: direct routes and indirect routes.

  • Direct routes: Connect directly with the mobile operators of the destination country. They are the most reliable and recommended, though they are also more expensive. These routes offer greater security, reliability, high service availability, notification in case of incidents, high delivery rates, and compliance with data protection legislation.
  • Indirect routes: Include intermediaries and are classified according to the number of hops (1 hop, 2 hops, etc.). Grey routes are a type of indirect route, characterized by their low cost but with significant disadvantages in terms of reliability and regulatory compliance.

The advantages of direct routes are many, including:

  • Connection security
  • Delivery reliability
  • High service availability
  • Notice and notification in case of incidents or scheduled maintenance
  • High delivery and conversion rate
  • Confirmation or error delivery report
  • Compliance with data protection legislation

However, direct routes may require some restrictions and conditions depending on the country or operator, such as:

  • Pre-registration of the sender by providing official data and completing a prior registration before sending.
  • Pre-registration of content based on templates with variables that must be submitted and approved in advance.
  • Sending restrictions by schedule or holidays
  • Content restrictions: political, official aid, tobacco, etc.
  • Specific regulations by sector or content, such as collections.

This classification is very important if our service or SMS communication need requires a high delivery rate. It is always recommended to opt for a direct route to obtain maximum delivery rate or reliability despite its higher cost.

Within the indirect routes, we find grey, wholesale, or low-quality routes that guarantee only partial delivery and may suffer blockages or incidents without the possibility of obtaining support or traceability.

Grey Routes

Grey routes do not have direct agreements with mobile operators and do not comply with established regulations, which can result in legal and reliability issues. These routes are divided into two types:

  • Wholesale Routes: Use roaming agreements to send messages at low cost, redirecting them through several countries. Although they are economical, they have a low delivery rate and may experience service interruptions without prior notice.
  • SIM Routes: Simulate sending messages between people using multi-SIM devices. They always deliver messages with a mobile number as the sender. These routes are frequently blocked by operators due to their non-compliance with regulations and are therefore unreliable.

Disadvantages of Grey Routes

Despite their attractive cost, grey routes present several disadvantages:

  • Non-compliance with GDPR: Grey routes can transfer data outside the European Union without authorization, which can result in significant fines.
  • Legal issues: Using grey routes can violate local communication regulations, exposing companies to sanctions and legal problems.
  • Low reliability: High probability of message delivery failures and information loss.
  • Service interruptions: Messages may not reach their destination due to service interruptions. Delays in delivery: Indirect routes can cause significant delays in the delivery of urgent messages.
  • Reduced functionality: Limitations in message customization and scheduling, affecting the effectiveness of marketing campaigns.
  • Lack of reports: Grey routes do not provide reliable metrics, making it difficult to evaluate the success of campaigns.

Control and Metrics in Grey Routes

The main problem with grey routes is the lack of control and traceability. Companies using these routes cannot obtain reliable delivery confirmations, making it difficult to evaluate the effectiveness of their SMS marketing campaigns.

Due to the exponential increase in fraud, phishing, and other bad practices in the SMS channel, mobile operators have increased and improved the detection of grey routes to be able to monitor and control SMS traffic.

It is crucial to opt for recognized services that use direct routes, ensuring reliability and compliance with legislation. At LabsMobile, all routes used are direct and comply with local regulations, ensuring high quality in message delivery.


Although grey routes may seem like an economical option for sending mass SMS, their multiple disadvantages make them an unadvisable choice. Direct routes, though more expensive, guarantee greater reliability, security, and regulatory compliance, translating into more effective SMS marketing campaigns and without legal risks.

If you are interested in our services and SMS routes, our technical and management team is available to answer all your questions and help you implement any SMS marketing action or campaign.

For more information, visit LabsMobile or contact us through our web form.

Our team advises you

Interested in our services?

Our managers and technical team are always available to answer all your questions about our SMS solutions and to advise you on the implementation of any action or campaign.

Contact us