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SMPP Statuses   If your SMPP SMS messages were not delivered as expected, you can use the Message Search tool under the SMS tab on the Sinch Customer Dashboard to view a report of messages you have sent using the SMS API. The entries in this report will include any messages that have been processed (or, in some cases, are in process).   Additionally, the Status column in the report will provide you with information on the current state your message is in:   Rejected   Message was rejected by Sinch. Sinch does not charge for rejected messages.   Troubleshooting Steps: If you receive the Rejected status for any of your SMPP SMS messages, we recommend you take the following Troubleshooting steps: Verify Number Format: Ensure the recipient's phone number is correctly formatted and valid. Incorrect formats often lead to rejection. Check Content Compliance: Review the message content for adherence to carrier and destination regulations. Non-compliance can result in rejection. Examine Sender ID: Confirm that the Sender ID used is approved and not causing the rejection, as some carriers have specific Sender ID policies. No Delivery Receipt   The operator did not provide a delivery receipt for this message.   Troubleshooting Steps: If you receive the No Delivery Receipt status for any of your SMPP SMS messages, we recommend you take the following Troubleshooting steps: Verify Number Format: Ensure the recipient's phone number is correctly formatted and valid. Incorrect formats often lead to rejection. Carrier and Network Check: Investigate any known issues with the recipient's mobile carrier or network delays that could prevent delivery. Pending Delivery Receipt   Awaiting delivery receipt for this message from the operator.   Troubleshooting Steps: If you receive the Pending Delivery Receipt status for any of your SMPP SMS messages, we recommend you take the following Troubleshooting steps: Check Network Conditions: Verify any known network issues that might be delaying message delivery, such as congestion or outages. Message Queue Status: Investigate if there's a high traffic backlog in Sinch causing delays. Content and Format Compliance: Ensure message content and format meet carrier and destination regulations to avoid pending status due to filtering or format issues. Recipient Device Status: Confirm if the recipient's device is on and within service range, as its status can impact delivery. Failed Messages which show a status of Failed will have an associated Error Code. Please refer to the SMPP Error Codes section for details of how to understand and troubleshoot common SMPP Error Codes.     SMPP Error Codes   If any of your SMPP SMS message search results have a Failed status, they will include an error code. These error codes are detailed in our developer documentation, and can be divided into Temporary and Permanent errors. Temporary errors indicate a state that may be resolved without changing the corresponding send message request. In these cases, retrying the same send message request may result in success as circumstances change. Permanent errors indicate a state in which the corresponding request must be updated in order to resolve the issue. For example, including a non-existent MSISDN in a send message request would result in a Permanent error; the MSISDN would need to be updated in order to resolve the issue.   The most common codes are listed below:   Error Code Treated as Description Comment/Action Troubleshooting Tips 61 Permanent Destination blocked. Account not permitted to reach the destination MSISDN Use the Right Account or Service: Make sure you are using the appropriate account or service for the destination you're trying to reach. Number Format Check: Ensure the phone number is in the correct E-164 format. It should start with the country code and be followed by the phone number, like “11234567890”, without including the '+' sign. Learn more.  Note: If the person has chosen not to receive messages (opted out), try reaching them in an alternative manner or avoid texting this number again. 62 Permanent Keyword blocked. A phrase or word in the body of the message has been caught in the anti-spam filter Review and Compliance: Carefully examine your message for any high-risk phrases, links, or keywords and make sure it adheres to the specific rules and regulations in your area. Learn more about content review and local compliance.  Test Message: After reviewing and adjusting your message, send a test version to ensure it successfully goes through without any issues. 150 Permanent Unknown subscriber The MSISDN is not active with the carrier Number Format Check: Ensure the phone number is in the correct E-164 format. It should start with the country code and be followed by the phone number, like “11234567890”, without including the '+' sign. - Learn more for iOS - Learn more for Android. Confirm Phone Number Validity: Ensure that the phone number you are trying to message is valid and currently active. Check that it is not blocked or restricted in any way on your account. Restart the Phone: Message Recipient may need to turn the phone off and then on again to refresh its connection. Test Another Number: Try sending a message to a different number on the same network to pinpoint the issue. Wait and Retry: If the issue persists, give it some time and then try sending the message again later. 151 Permanent Call barred. Message rejected due to active barring by the end-user. The person receiving the message needs to call their mobile service provider to fix any blocks on their account. It might be best to stop sending messages to this number for now. 153 Temporary Absent subscriber. Subscriber handset not connected to the network. Likely turned off or outside the area of coverage. Check the Phone Number: Make sure the number is correct and working with the mobile service provider. Check the Phone: Message recipient may need to confirm the phone is on and has a strong signal. Restart the Phone:    Message recipient may need to turn the phone off and on again to refresh its connection. Wait and Retry: If the issue persists, give it some time and then try sending the message again later. 158 Temporary Memory capacity exceeded. The handset does not have sufficient free memory to accept the SMS Message recipient may need to make sure the phone has enough space for new messages. Delete old texts if necessary. 212 Temporary Device not short message equipped. The number cannot receive text messages, for example Data-SIMs Check Number Type:  Message Recipient may need to ensure the number can receive texts. It shouldn't be a data-only SIM card, landline, VoIP, or any special service number that can't get text messages. 255 Permanent Personal service barring, MT Personal. Determined Barring Black List. The end-user has opted out from receiving messages. Either all A2P messages or sender ID specific Check for Blocks: Ensure no filters or bars are preventing the number from receiving messages. Contact Support: If you're unsure, reach out to your service provider’s help team. Test Message: Send a test message to ensure the issue is resolved. 300 Permanent Invalid destination address The MSISDN does not exist Number Format Check: Ensure the phone number is in the correct E-164 format. It should start with the country code and be followed by the phone number, like “11234567890”, without including the '+' sign. Learn more.  Confirm Phone Number Validity: Ensure that the phone number you are trying to message is valid and currently active. Check that it is not blocked or restricted in any way on your account. Follow the Rules: Ensure your message meets all the local laws. Check the rules. For Developers: If using SMPP, set TON/NPI values to 1/1. 310  Permanent Invalid source address The source address is not permitted. Refer to Country Information and local regulations Check Sender Name/Number: Make sure the sender ID is set up properly. Follow the Rules: Ensure your message meets all the local laws. Check the rules.   Note: Refer to the Sinch SMS SMPP Developer Documentation for a complete list of all the SMPP error codes. ... View more

Short Message Service (SMS) is the telecommunications industry term for a text messages or short messages which are messages of up to 160 characters in length sent by smart phones, mobile phones or tablets. Messages of more than 160 characters can be sent, but these will be sent as multiple messages concatenated to appear as one message, for which you could be charged more.    Note: Once an SMS is concatenated, the SMS will be shortened, for example, 153 characters instead of 160.   SMS is a hugely popular method of communication and billions of messages are sent every day (source).   Take a look at the Sinch SMS Product page to learn more about our SMS products, or click here to sign up to our self-service portal and get started today. ... View more

Commonly referred to as text messaging, SMS stands for Short Message Service, but how does SMS work? At a high level it is very simple but the first thing you need to understand is the difference between Person to Person text messaging (P2P) and Application to Person text messaging (A2P). For those of you who already know the basics and want the hardcore technical details please read on…   Person to Person (P2P) SMS and the Need for an SMSC Text messaging is part of our everyday activities and most of us send and receive P2P text messages throughout the day. There are literally trillions of P2P text messages sent and received every year, but with mobile applications such as WhatsApp and Viber, the volume of P2P text messages is starting to decrease, and the volume of OTT (Over the Top) messages sent through mobile applications is growing.   The sender of the text message, is a mobile subscriber of operator A; while the person who the text is being sent to is a mobile subscriber of operator B. Once the person has hit “Send” on their mobile phone, the text message is sent to their home operator (for example, AT&T). Every mobile operator has a machine called an SMSC (Short Message Service Center).   An SMSC is simply a computer system, running specific software inside of the mobile operator’s network and is designed to receive the text message from you and to deliver the SMS to your friend’s phone through their mobile operator as quickly as possible.   The mobile operator’s SMSC will deliver the message directly to your friend’s phone if the operator has reach (the ability to connect) via an SS7 network. If the operator does not have reach through an SS7 network, it will instead use what is called a P2P hub to deliver the message. A P2P hub is actually a company whose business is to pass messages between mobile operators that can’t send messages directly to each other.   Three important things to note are: In most cases an SMS will only be stored by one SMSC (usually the home operator) before final delivery to the intended handset An SMSC can deliver to any handset in the world where the home operator has reach In the USA all P2P messages are sent via a hub so at least two SMSC’s will be used to deliver the message. Application to Person SMS (A2P SMS) A2P SMS message delivery works in a similar fashion, with the key difference being instead of two people communicating through mobile phones, the communication is between a computer application and a person. An example of this is when you receive a text message from your bank or other business. To illustrate this, see the following example:     The mechanics in sending an A2P SMS are similar to P2P SMS. Messages flow via the mobile operators’ SMSCs but the key difference is that the message is sent from an enterprise (a business entity) instead of a person. At this point it is worth mentioning the two directions in which an SMS message can flow. When it is sent to a mobile phone the text message is referred to as a Mobile Terminated (MT) message, subsequently when a message is sent from a mobile phone it is called a Mobile Originated (MO) message. The way in which the message is delivered is exactly as shown above. When a message is delivered by an SMSC it will return a Delivery Notification to the enterprise providing proof the message was delivered, or the reason for why it failed.   The Need for a Cloud Messaging Provider or Aggregator An enterprise or small business could choose to directly connect to one mobile operator to handle the delivery for all their messages, but since no single mobile operator can reach every operator means there are messages that will go undelivered. On the other hand, the enterprise could choose to have direct connections to several mobile operators at once, this becomes complicated real fast. Most enterprises would not choose to connect to multiple operators and have the overhead of managing each one and negotiating separate commercial contracts and technical integrations, hence the need for an aggregator. So, what’s an aggregator? It is a business that takes care of the technical and commercial complexities for enterprises and provides them the most cost-effective price to deliver anytime, anywhere.     In some cases, an enterprise will use another partner who specializes in marketing, multi-channel communications, or a vertical specialty to send their SMS messages on their behalf, these are referred to as an Application Service Provider (ASP) or communication provider.   Take a look at our SMS Product page for more product information, or click here to sign up to our self-service portal and get started today. ... View more

A cloud service is a service provided to clients on demand over the internet from the cloud computing provider’s servers (hardware). This removes the need for a client to have their own on-premise servers to host and run the software. The Sinch cloud-based SMS service can be accessed through our comprehensive set of Messaging APIs.   Creating your own SMS application is simple using the Sinch cloud-based SMS service, you can try our APIs – they’re easy to use and there is always expert help at hand if you need it. For more in-depth of our powerful APIs take a look at our Developer Documentation.   For more information on the cloud SMS services that Sinch offer take a look at our SMS product page. ... View more

SMS traffic can be classified as either Application-to-person (A2P) or Person-to-person (P2P).  P2P messaging is personal messaging the end-user to end-user traffic we all use in daily life. When a person sends a text message to their family or friends using a handset or messaging app, it is a P2P message. A2P messaging refers to messages for business use. Most traffic sent programmatically by enterprises in large batches using webs tools or APIs integrated with their internal systems is A2P traffic. A2P has some benefits, for example, the ability to customize routing to optimize costs and additional transparency about delivery success. At the same time, A2P is scrutinized and regulated to prevent SMS spam. A2P regulations vary from country to country and navigating the regulatory requirements of a global SMS campaign can be daunting.   Note: The Sinch Customer Dashboard contains comprehensive Country Information pages, which detail regulatory and compliance information to help you communicate successfully with different countries.   Sinch has experts in major markets around the world that can guide you and ensure a successful SMS campaign - Learn more about Sinch. ... View more

Text messages are an ideal way to engage with your customers and increase response rates. Open rates for text messages are very high – amongst the highest open rate for marketing / promotional material at over 90% (source).   Take a look at the Sinch SMS Product page to learn more about our SMS products, or click here to sign up to our self-service portal and get started today. ... View more

One of the things that makes Sinch a leader in the mobile messaging market is our vast number of direct connections. Over the years we have built relationships with suppliers and operators that allow us to reach all four corners of the globe. Sinch currently serves over 200 destinations and thousands of networks, and we are confident we can get your message to your audience.   When sending messages to different countries, customers are obligated to comply with all applicable regulations and requirements pertaining to that country. The Sinch Customer Dashboard contains comprehensive Country Information pages, which detail regulatory and compliance information to help you communicate successfully with different countries. ... View more

Features and restrictions of mobile messaging vary around the world depending on regulations, routes used and operators. We monitor the features we can provide to our customers, to give you a better idea of what features you can use in each particular destination.   The Sinch Customer Dashboard contains comprehensive Country Information pages, which detail regulatory and compliance information to help you communicate successfully with different countries. When sending messages to different countries, customers are obligated to comply with all applicable regulations and requirements pertaining to that country.   Take a look at the Sinch SMS Product page to learn more about our SMS products, or click here to sign up to our self-service portal and get started today. ... View more

Yes, it is possible to send a message to more than one country at a time. You just need to ensure that when you send messages to international numbers, you have the appropriate country code in front of each number so that they can be routed correctly.   However, please be aware that as messages are charged per network / destination, costs may vary on messages sent internationally - for more information refer to our SMS product page.   Note: When sending messages to different countries, customers are obligated to comply with all applicable regulations and requirements pertaining to that country. The Sinch Customer Dashboard contains comprehensive Country Information pages, which detail regulatory and compliance information to help you communicate successfully with different countries. ... View more

When you send a text or SMS to another country, the cost depends on whether the phone you are sending messages to, is in another country roaming, or if it originates from the country being texted. There is no extra charge to send a text message to a phone that is roaming in another country, but if the SIM originates in another country charges will apply. The charges can vary depending on the carrier and the destination country.   As messages are charged per network / destination, costs may vary on messages sent internationally - for more information and to learn more about SMS Messaging from Sinch, refer to our SMS product page.   Another option is to use messaging apps that use an internet connection, such as WhatsApp or Facebook Messenger, as these may allow you to send messages to other countries without incurring additional fees. However, it's important to note that both you and the recipient need to have the app and an internet connection for this to work. The Sinch Conversation API offers one single API endpoint for sending and receiving messages globally across the most popular channels including, SMS, RCS, WhatsApp, Viber Business, Facebook messenger and other popular channels.    Note: When sending messages to different countries, customers are obligated to comply with all applicable regulations and requirements pertaining to that country. The Sinch Customer Dashboard contains comprehensive Country Information pages, which detail regulatory and compliance information to help you communicate successfully with different countries. ... View more

Delivery receipts are information packets that have been generated by the handset. If the handset is not equipped to show the message, but has received the signal from the sender, an issue can arise where you can receive a successful delivery receipt, but it has not been fully received.   In this case your recipient may never have seen the message. This is particularly common with older handsets where the memory is not enough to display the message in its entirety. If you believe this is happening contact Sinch Support who we will investigate the issue further for you. ... View more

Each destination has its own particular rules and regulations regarding what type of sender ID can be used. Restrictions are put in place by Carriers and can result in some message sender IDs being overwritten or failing. In some destinations sender IDs also need to be pre-registered to be accepted by the carrier. Read the How to register your alphanumeric sender ID? article for details of how you can easily register your sender ID with Sinch.   The Sinch Customer Dashboard contains comprehensive Country Information pages, which includes information about Sender ID requirements, and regulatory and compliance information to help you communicate successfully with different countries.   Note: When sending messages to different countries, customers are obligated to comply with all applicable regulations and requirements pertaining to that country.   We are constantly monitoring network restrictions and can assist you with ensuring your messages are delivered. If you are experiencing any issues with sender IDs please reach out to the online team or to your Sinch Account Manager if you have one.   Take a look at the Sinch SMS Product page to learn more about our SMS products, or click here to sign up to our self-service portal and get started today. ... View more

No. Sinch keep message logs for 14 days, but all messages are depersonalized and archived. If you are using an API, it’s your responsibility to retrieve and store delivery reports as required.   Take a look at the Sinch SMS Product page to learn more about our SMS products, or click here to sign up to our self-service portal and get started today. ... View more

Yes. Two-way messaging is possible through the rental and use of a virtual number. However, not all destinations support the ability of two-way messaging. Please contact your Account Manager to determine whether or not your targeted destination supports two-way SMS.     Note: When sending messages to different countries, customers are obligated to comply with all applicable regulations and requirements pertaining to that country. The Sinch Customer Dashboard contains comprehensive Country Information pages, which detail regulatory and compliance information to help you communicate successfully with different countries.   Take a look at the Sinch SMS Product page to learn more about our SMS products, or click here to sign up to our self-service portal and get started today. ... View more

When you sign up online for an account with Sinch you will be given some test credit to allow you to start sending messages immediately. You can use this credit to test the service we provide. Sign up for your account to get started.   Watch our short Get started with Sinch SMS video to learn how easy it is to send your first message.    Note: Due to fraudulent use of this credit in the past, you can now only test our service by sending the standard sample message we have created. Once you add credit to your account you are free to personalize messages as you require.   If you would like to get in touch to discuss testing the system for a potentially large account, please contact Sinch. This is something we can look at on a case-by-case basis, but as a general rule, once the test credit is used up you will need to pay for all further messages sent.   Learn more about Sinch’s SMS Products. ... View more