Frequently Asked Questions (FAQ)

Here are the answers to the most relevant issues and most common problems. If you don't find an answer to a problem, please contact our support for further information.




How do I change my personal settings or check my personal ASPSMS balance? [Q1014]
Just login with your personal username and password. After the login you have full access to your account information and your personal settings. You may change your settings at any time. Your remaining credit balance is always visible in your account dashboard and can also be queried programmatically via the API.


Do I need additional software to set up ASPSMS? [Q1015]
No, you don't need additional software! Just login and follow our instructions to set up ASPSMS. Please have a look at our useful example collection.


Does JavaScript have to be activated? [Q1016]
To provide all the functionalities of the website, JavaScript is required. (was: To provide all functionalities, JavaScript is required.) If you encounter problems, please check your browser settings to make sure that JavaScript is active.


How many countries are supported? Which roamings are activated? [Q1017]
ASPSMS covers over 900 mobile operators in more than 200 countries. Please go to the following page to get the updated coverage list. At no additional roaming surcharge beyond the standard per-country credit rate, you can reach recipients worldwide.


Do you support Arabic characters? [Q1018]
Yes, we do. It is possible to encode an Arabic message with UCS2 (HexEncoded). Please have a look at our detailed help page for Arabic characters. We also support other character encodings.


I develop and distribute a program and would like to integrate your SMS component. Is that allowed? [Q1021]
Yes of course. We offer attractive affiliate programmes for developers, portals, ISPs, magazines, download sites, and individuals. Please take a look at the two possible affiliate models. You can either register and get some free test credits, or simply contacty/a> our affiliate program manager, who will be happy to assist you and answer your questions.


Why are the last 3 digits of the originator replaced with 'xyz'? [Q1041]
There are certain restrictions if you would like to use numeric originators (e.g. '+41791234567'). Numeric originators may only be used if they have been unlocked in advance with an Unlockcode. This Unlockcode is sent to the corresponding mobile phone which should be used as the originator. Please be aware that many operators outside Switzerland automatically replace a numeric originator with a general originator, even if you have unlocked the numeric originator.

Important: You only need to follow this procedure if you plan to use numeric originators. If you use alphanumeric originators (e.g. 'MYSHOP'), there are no restrictions. Please note that misuse will in every case be prosecuted according to the terms of Civil and/or Criminal Law.

Originators from devices not capable of receiving SMS (e.g. fixed-line numbers) cannot be unlocked automatically. If you would like to use such a number, please contact support.


What is ASPSMS and what does it offer? [Q1049]
ASPSMS is a professional Swiss SMS gateway operated by VADIAN.NET AG, a company founded in 1995 and based in Switzerland. The platform allows businesses and developers to send and receive SMS messages programmatically via multiple integration methods, without needing their own telecom infrastructure. Use cases include transactional notifications, marketing campaigns, two-factor authentication (2FA/OTP), appointment reminders, alerts, and bulk messaging. ASPSMS has been serving customers since 2001 and today supports over 200,000 business clients worldwide.


Is ASPSMS suitable for small businesses as well as large enterprises? [Q1050]
Yes. The pricing model is fully volume-based — no setup fee, no monthly subscription, no minimum commitment. A small business sending a few hundred appointment reminders per month pays only for those credits, while a large enterprise running daily bulk campaigns benefits from volume discounts. Over 200,000 business clients of all sizes currently use the platform, from single person companies to international corporations.


Where is my data stored? Is it subject to Swiss or EU law? [Q1068]
All data is stored exclusively in Switzerland, in the Tier IV East Switzerland Data Center. Since Switzerland has its own strong federal data protection law (DSG) and is recognised by the EU as a country providing adequate data protection, your data benefits from privacy standards equivalent to European GDPR. No data is routed through or stored outside Switzerland. VADIAN.NET AG is an ISO 27001 certified and OFCOM-registered Swiss telecommunications provider.


Is ASPSMS GDPR-compliant? Can we sign a Data Processing Agreement (DPA)? [Q1069]
Yes. Because all infrastructure is Switzerland-based and VADIAN.NET AG is ISO 27001 certified, ASPSMS meets GDPR requirements for organisations sending SMS to recipients in the EU/EEA. A Data Processing Agreement (DPA) can be arranged for customers who require it for their own compliance documentation. Please contact the ASPSMS support or sales team to request one.


What are the legal requirements for sending marketing SMS in Switzerland and the EU? [Q1070]
For marketing SMS you must comply with the applicable law of the recipient's country:

• Switzerland – the Unfair Competition Act (UCA / UWG) and other regulations prohibits unsolicited commercial electronic messages. Explicit prior consent (opt-in) from recipients is required.
• EU / EEA – the ePrivacy Directive and GDPR require freely given, specific, and documented consent for direct marketing.
• Always provide a clear opt-out mechanism (e.g. "Reply STOP") in every marketing message.
• Keep records of consent for audit purposes.

Transactional SMS (order confirmations, appointment reminders, OTPs) generally do not require marketing consent, but must still comply with applicable data protection rules. We recommend consulting a legal advisor for your specific use case.


Does ASPSMS have a Service Level Agreement (SLA)? [Q1071]
Yes. A formal Service Level Agreement is available for business customers. The SLA documents the guaranteed uptime, response times, and support commitments. Please refer to the Service Level Agreement page or contact sales for enterprise-grade SLA terms.


What is ASPSMS's uptime and reliability? [Q1065]
ASPSMS infrastructure is hosted at the East Switzerland Data Center (Rechenzentrum Ostschweiz), a Tier IV certified facility offering 99.995% availability — the highest standard available. VADIAN.NET AG has operated the platform since 2001, holds ISO 27001 certification for information security management, and is an OFCOM-registered Swiss telecommunications service provider (licence 254900005). Real-time system status is published on the System Status page.


Why do some SMS show as undelivered? What can I do about it? [Q1066]
Undelivered messages typically fall into a few categories:

• Invalid number – the recipient number does not exist or is incorrectly formatted. Always use E.164 format.
• Phone switched off or out of coverage – the message may be retried automatically until its validity period expires.
• Network filtering – some operators filter messages from certain originator types or content patterns, particularly on prepaid numbers.
• Regulatory blocking – certain countries restrict specific sender types or require local registration.

Review delivery reports (DLR) via webhook for per-message status codes. Regularly cleaning your contact list of permanently unreachable numbers improves delivery rates and reduces costs.


Do credits expire? [Q1051]
ASPSMS credits do not expire. Once purchased, your balance remains in your account indefinitely. This makes it practical for businesses with seasonal or unpredictable SMS volumes — you can buy a larger bundle at a better price without worrying about a use-by deadline.


Are volume discounts available for high-volume senders? [Q1052]
Yes. The more credits you purchase at once, the lower the price per credit. Volume tiers are clearly listed on the pricing page. For very high-volume requirements or enterprise contracts, please contact the ASPSMS sales team directly to discuss a tailored agreement.


Why does sending an SMS to a Swiss Salt number cost more credits than to Swisscom or Sunrise? [Q1053]
In Switzerland, the actual network operator of the recipient number is checked before an SMS is sent. SMS to numbers registered with Salt or an associated mobile virtual network operator (MVNO) are charged at 1.75 credits, while SMS to Swisscom or Sunrise numbers are charged at 1 credit. This reflects the different termination fees charged by each operator. The current Swiss rate details are published on the Switzerland networks page. International networks and their rates are listed on the supported networks page.


How long does it take until my credits are available or my Global Two-Way number is activated? [Q1026]
Please note that we usually unlock your credits or the purchased Global Two-Way number immediately during office hours, but at the latest within 24 hours. You can set a Credit Warning with several warning levels and recipients so you are notified automatically when your balance runs low.


How much does ASPSMS cost? [Q1007]
There is no setup fee or any other basic fee. The software is free of charge. You simply pay per SMS you send. You pay in advance using our secure online credit card application (SSL) or by bank transfer to our account. Your personal SMS balance is always accessible for you to check in your SMS account. Please refer to the price list for current prices by country and volume.


Why do you bill in advance? [Q1011]
To reduce handling costs of invoicing and to give fast access to a modern and efficient application. The price per SMS is based on the volume that you pay in advance. The more you order, the better the price.


How secure is the online payment by credit card? [Q1012]
The transaction is very secure. We use SSL (Secure Socket Layer) for secure data transmission. ASPSMS uses the service of Saferpay to transfer the credit card data. Saferpay is the largest provider for electronic payment services in Switzerland. We accept Mastercard, Visa, Diners Club, American Express, Postcard, TWINT, and bank transfer.


What is a UserKey? Where do I find it? [Q1010]
The UserKey is a unique key associated with your account. It is a security feature. You need to set the UserKey in your ASPSMS application together with your personal password. Login to your account and navigate to API Credentials.


Do I need to register by e-mail, mail or fax? [Q1019]
No! Registration, activation and settings are completed entirely online. Simply visit aspsms.com/en/registration/ and follow the on-screen instructions.


Why did I not get an e-mail after registration? [Q1031]
Check the settings of your spam filter. It is possible that the confirmation e-mail was filtered. If the problem persists, please contact our support team.


How does two-factor authentication (2FA) work with ASPSMS accounts? [Q1054]
ASPSMS has enabled two-factor authentication via email for all customer accounts to enhance account security. When you log in, you will receive a verification code by email in addition to entering your password. We recommend keeping your account credentials up to date.


Why do I need a username and a password? [Q1000]
For clear authorisation and access to your protected personal account. We use your email address as username. In case of a problem, this will help us to contact you as soon as possible.


Where can I find information about planned maintenance or service disruptions? [Q1072]
Real-time system status and maintenance announcements are published on the System Status page. Registered customers are also notified of planned maintenance windows via the ASPSMS newsletter. We recommend subscribing to the newsletter to receive timely notifications.


How do I get support? [Q1013]
For technical support and marketing questions, please use our support contact page. Our Swiss-based support team speaks German, French, and English and operates in Central European time. For self-service, the following resources are also available:

• API Documentation.
• Code Examples (C#, PHP, Java, Python, Node.js, and more).
• Blog & Knowledge Base.
• Newsletter Archive.

Which IP addresses or ports do I need to whitelist in my firewall? [Q1020]
If your server operates behind a firewall and needs to reach an ASPSMS API, ensure that outbound HTTPS traffic on port 443 is permitted to the corresponding aspsms.com domain, e.g. json.aspsms.com. (was: If your server operates behind a firewall and needs to reach the ASPSMS API, ensure that outbound HTTPS traffic on port 443 is permitted to the aspsms.com domain.) For specific IP ranges used by the ASPSMS gateway infrastructure, please consult the System Infrastructure page or contact support, as addresses may be updated during infrastructure changes.


Why is the originator set to 'SMS'? [Q1024]
Some networks require an alphanumeric originator. If a numeric originator is used and the network does not support it, it will be changed to the value "SMS" or to similar general originator. If an alphanumeric sender is used by default, it will be forwarded without change to the destination network but a mobile operator can still automatically replace the originator with a general originator, if it is needed in that specific country.


Are there any restrictions with alphanumeric originators? [Q1042]

ASPSMS does provide an alphanumeric originator function (for example a company name as originator) since 2001 and was one of the first SMS providers that has implemented this functionality. ASPSMS continues to provide this function generally, but unfortunately some of the operators have begun to block that feature in their GSM networks. Unfortunately ASPSMS cannot do anything about this restriction, because it is implemented directly by the specific destination mobile operator.

ASPSMS is informing in its network list about the GSM networks with restriction for alphanumeric originators.

ASPSMS has implemented an easy way which is automatically taken into use for those GSM networks which don’t allow anymore an alphanumeric originator to go through.

If a client sends a SMS with an alphanumeric originator to a specific GSM network which is blocking alphanumeric originators, ASPSMS automatically converts that alphanumeric originator to a system generated numeric originator. That allows the SMS to go through. If a numeric originator is used, it will be forwarded without change to the specific destination network.

For these networks with an alphanumeric originator restriction, ASPSMS recommends all the clients to use own numeric originator or purchase a global two-Way number from ASPSMS, which can be used as a numeric originator. However, because of this automatic conversion (alphanumeric originator->numeric originator) by ASPSMS, client doesn’t necessarily have to do any changes.

Are there any restrictions with numeric originators? [Q1043]

ASPSMS has provided a numeric originator function (normally a mobile phone number) since 2001. ASPSMS continues to provide that function generally, but unfortunately some of the operators have begun to block some of the numeric originators in their GSM networks. Normally blocking emerges only when using a local inland number is specified as an originator.

ASPSMS is informing in its network list about the GSM networks with restrictions for numeric originators.

If there is a restriction with numeric originators in a specific network, the SMS behaviour is not always the same. Scenarios below are possible, when sending with a numeric originator to a restricted network:

• SMS with an inland number as an originator is not going through, but SMS with originator number from abroad is going through without problems.
• SMS is going through but the destination network automatically changes originator to a specific short-code.
• SMS is going through without problems.

Unfortunately ASPSMS cannot do anything about these restrictions, because it is implemented directly by the specific destination mobile operator. ASPSMS recommends users to test the specific numeric originator, when sending to networks which are marked as restricted.

For these networks with a numeric originator restriction, ASPSMS recommends clients to use an international numeric originator or purchase a global two-Way number from ASPSMS, which can be used as a numeric originator.

My software no longer connects to the ASPSMS SOAP web service [Q1045]

There may be problems with the handshake for encryption because a component used by your system (such as OpenSSL) was updated.

Because there are reasons why we can not update the infrastructure that hosts the webservice.aspsms.com interface to the latest encryption technology, we run the same web service on a second infrastructure that is up-to-date:

• OLD: webservice.aspsms.com (194.230.72.34)
• NEW: soap.aspsms.com (194.230.72.69)

Please use https://soap.aspsms.com/aspsmsx2.asmx as api for sending sms:

ASPSMS SOAP Web Service
http://www.aspsms.com/en/soap/
Der ASPSMS SOAP Web Service must be connected on the following address:

• NEW: soap.aspsms.com (194.230.72.69)

Ports:

• HTTP: 80
• HTTPS (SSL): 443

Please take note of the firewall rules, which regulate access to our interface.

Why are multiple SMS sent for a single message? [Q1047]
Technically, a standard SMS can contain a maximum of 160 characters. If a message is longer, it is automatically split up. Each part is sent as a separate SMS so that the recipient receives the message in its entirety. On most devices, the parts are reassembled and displayed as a single continuous message. Because the concatenation header takes up space, only 153 characters are available per partial SMS. ASPSMS supports concatenated SMS of up to 9 parts, allowing messages of up to 1,377 characters in total.


Which API protocols and integration methods does ASPSMS support? [Q1055]
ASPSMS provides a broad range of interfaces to fit any technology stack:

• JSON API (REST) – modern RESTful API with JSON payloads, recommended for new integrations.
• WebAPI – extensive web API returning a JSON object.
• HTTP-POST – simple HTTP GET/POST requests, suitable for any programming language.
• SOAP Web Service – full-featured interface supporting all advanced options.
• XML – powerful interface for Unix/Linux developers.
• SMTP (Email to SMS) – send SMS by email, no programming experience required.
• ActiveX / COM Component – Windows component, e.g. for ASP or Visual Basic environments.
• Microsoft Power Automate / Zapier / Make – no-code/low-code workflow connectors.

Full documentation and code examples in C#, PHP, Java, Python, Node.js, VBScript, and more are available in the documentation section.


Can I customise the sender name (originator) shown on the recipient's phone? [Q1056]
Yes. ASPSMS supports two originator types:

• Numeric – a valid phone number in E.164 format (e.g. +41790000000). This allows two-way communication (the recipient can reply), but must be unlocked with an Unlockcode first.
• Alphanumeric – up to 11 characters (letters and numbers), such as your company name or brand (e.g. "ASPSMS" or "MyShop"). Alphanumeric senders are one-way only and may not be supported on all networks in all countries.

Always verify the rules for each destination country, as some markets restrict or disable alphanumeric originators.


Does ASPSMS support two-way SMS (receiving replies)? [Q1057]
Yes. ASPSMS offers a Global Two-Way SMS service. You can rent a virtual inbound number and receive incoming SMS to your application via a configurable webhook (callback URL). This enables interactive campaigns, keyword-based opt-outs, survey responses, and customer service flows. No SIM cards are needed, setup is fast, and there is a low monthly fee per number. See the Two-Way Coverage and Two-Way Prices pages for details.


Can I get delivery reports to confirm an SMS was received? [Q1058]
Yes. Delivery notifications (DLR) are a standard feature. You can configure a callback URL (webhook) in your account or per API call. When the mobile network confirms delivery, ASPSMS posts the status (delivered, failed, expired, etc.) to your endpoint in real time, allowing your application to track success rates, trigger follow-up actions, or flag undelivered messages for retry.


Does ASPSMS support 2FA / OTP (one-time password) use cases? [Q1059]
Yes. Two-factor authentication and mTAN/OTP delivery are among the most common business use cases on the platform. The ASPSMS ASPTOKEN product is purpose-built for 2FA integration. The API is fast enough for real-time authentication flows, and you can set a short message validity window so expired tokens are never delivered. ASPSMS is used by banks, SaaS platforms, and e-commerce sites in Switzerland and internationally for their 2FA infrastructure.


What number format should I use for recipient and originator numbers? [Q1060]
For both originator and recipient numbers, always use the international standard E.164 format: country code followed by the number, without spaces, brackets, points, or special characters. For example, a Swiss mobile number is written as +41791234567 or 0041791234567. A country code list is available on Wikipedia.


Can I schedule SMS messages to be sent at a specific time in the future? [Q1061]
Yes. ASPSMS supports scheduled sending. You can specify a future timestamp in your API call, and the message will be queued and dispatched at that exact time. This is useful for appointment reminders, time-sensitive campaigns, maintenance alerts, and automated workflows.


How do I send a bulk SMS to many recipients at once? [Q1062]
For bulk sending you have two main options:

• API bulk call – pass a list of recipient numbers in a single API request. This is the most efficient method for application-driven bulk sends.
• SMS Blaster – our SMS Blaster desktop tool and web edition allow you to upload a contact list, personalise messages, and launch a campaign without any programming. Ideal for marketing teams.

For large campaigns, our free Concierge Service can assist with setup and execution.


Is there a test environment or test credits available? [Q1063]
Yes. You can request free test credits after registering. Test credits allow you to send real SMS messages to verify your integration before purchasing a credit bundle. This ensures you can evaluate delivery speed, API behaviour, and delivery reports in your own environment with no financial commitment.


Is there documentation and sample code available for developers? [Q1064]
Yes. The documentation section contains full API references for all interfaces (JSON/REST, SOAP, HTTP, XML, SMTP, ActiveX). Ready-made sample code is available for C# (.NET Core and MVC), PHP, Java, Python, Node.js, VBScript, and more. The examples page provides copy-paste code snippets to get you started in minutes. ASPSMS is also available as a NuGet package for .NET developers.


What is the SMS character limit and what happens with special characters? [Q1067]
A standard SMS supports up to 160 characters using GSM-7 encoding. If your message contains characters outside the basic GSM-7 set (such as certain accented characters, emojis, Arabic, Chinese, or other Unicode scripts), the encoding switches to UCS-2, which reduces the per-message limit to 70 characters. For multi-part Unicode SMS, each part carries up to 67 characters. ASPSMS supports concatenated SMS of up to 9 parts (1,377 characters for GSM-7; 630 characters for Unicode). To keep costs down, avoid unnecessary Unicode characters and review your character usage before sending.


When sending an SMS I get the following error: "Could not complete the operation. One or more parameters are not valid." [Q1037]
You are probably using an old pst file. To get your personal data into a new pst file you have to create a new one and drag and drop all your personal data into the new file.