Austria sender registration guidelines
The Austrian regulator, Rundfunk und Telekom Regulierungs-GmbH (RTR), has introduced a national register for alphanumeric Sender IDs used for A2P SMS. The register is managed through the eRTR portal.
From 1 October 2026, only Sender IDs listed in the register may be delivered to Austrian mobile subscribers. Messages using an unregistered Sender ID are deleted by the network.
Key dates
| Date | Milestone |
| 14 August 2026 | Deadline for you to return your Sender IDs to us |
| 24 August 2026 | RTR deadline for bulk submissions |
| 4 September 2026 | RTR imports submissions into the register |
| 1 October 2026 | Blocking of unregistered Sender IDs begins |
Registration process
If we have emailed you
We have reviewed your account and identified the Sender IDs you use to send SMS to Austria. Your email contains a link to your registration page, where those Sender IDs are listed.
There are two things to do:
1. Validate your Sender IDs
Check the list and confirm which Sender IDs you want registered.
2. Add a justification for each Sender ID
RTR needs to know why your business has the right to use each Sender ID. Choose the reason that applies, for example, that it is your registered company name, your trade mark, or your web domain.
You will need to do this for every Sender ID individually. RTR reviews each entry separately, so one justification cannot cover them all.
Then sign the authorisation, which allows us to submit on your behalf, and send it to us by 14 August 2026.
If we have not emailed you
If you send SMS to Austria and have not received your registration link, contact our support team.
After you submit
We check your details and come back to you if anything needs correcting. We then submit to RTR ahead of the 24 August deadline. If RTR raises any queries or rejects your sender IDs, we will contact you to try to resolve any issues with your registration.
What makes a Sender ID acceptable
RTR will only register a Sender ID that clearly identifies the business sending the message. A Sender ID that describes the type of message, the industry, or the service in general terms will be refused, because it could belong to any sender.
| Not accepted | Why | Use instead |
| INFO | Describes the message, not the sender | Your company name |
| BANK | Describes an industry — it could be any bank | Your registered name or brand |
| DENTIST | Describes a profession, not a specific practice | Your practice name |
| DELIVERY | Describes the type of message | Your company or service brand |
Your Sender ID must be one of the following:
- It is your business name
- It is your intellectual property (eg trademark or brand, registered or unregistered)
- You are legally allowed to use this business, trademark or brand name on behalf of its owner
When you validate your Sender IDs, you will be asked to select which of these applies. RTR reviews each entry individually, so choose the reason for each Sender ID separately.
Sender ID format rules
RTR will reject a Sender ID that does not meet these rules:
| Rule | Requirement |
| Length | 1 to 11 characters |
| Allowed characters | A–Z, a–z, 0–9, spaces, and + – & _ |
| Must contain | At least one letter |
| Not allowed | Umlauts (ä, ö, ü), ß, and other special characters |
| Not allowed | Spaces at the start or end |
| Not allowed | Generic names such as “Info”, “Alerts” or “Reminder” |
Maximum of 40 Sender IDs per user within a rolling 6-month period
Registration is case sensitive. “MyBrand” and “MYBRAND” are treated as two different Sender IDs, so register only the version you actually send with.
If your Sender ID cannot be registered
Some Sender IDs in use today will not meet RTR’s rules. The most common reasons are a generic name, a numeric-only Sender ID, or a name containing an umlaut or ß.
Sender IDs are also registered first come, first served, so one already registered by another business cannot be registered again.
If any of these apply, you will need to move to a compliant Sender ID before 1 October 2026. This changes your sending configuration as well as your registration, so please contact our support team as early as you can.
What happens if you do not register
From 1 October 2026, messages sent from an unregistered alphanumeric Sender ID are blocked at network level:
- The message is not delivered
- No fallback is applied
- Your recipient sees nothing, and no error is returned to them
What the Register Publishes
The RTR register is a public open data register, refreshed daily and accessible through a public API. Every field you provide will be published, including your company name, postal address and contact email address.
These details must be those of the Sender ID holder — your business — and not those of your messaging provider or aggregator. Please make sure the contact email address you give us is one you are content to have published, such as a shared support or compliance mailbox rather than a named individual.
Common questions
Is the list of Sender IDs you sent me complete?
It covers the Sender IDs we have seen on your account. It will not include any you have not yet used, or plan to launch before October. It will also include non-compliant sender IDs. If you need to add sender IDs, please contact your account manager as soon as possible.
What if my business is based outside Austria?
The rules apply to any alphanumeric SMS delivered to an Austrian mobile subscriber, wherever your business is based. Traffic must be delivered through an authorised Austrian route, which we handle for you.
How long does registration last?
Registrations do not expire. RTR may delete entries that do not meet the rules.
Need help?
If you are unsure whether this affects you, or need help with your registration, contact our support team.
If you are a reseller providing services to your own end customers, contact your account manager.