From May 4, 2026, all SMS Sender IDs to Finland must be authorized or registered. Unregistered Sender IDs will be blocked, affecting SMS delivery.
This article explains what's changing, who is affected, and how to submit your Sender ID for compliance through Omnisend.
Before You Begin
This applies if you send SMS messages to Finnish mobile numbers using a custom alphanumeric Sender ID or a Finnish long number.
Required for: Promotional campaigns, transactional messages, and automated notifications sent via Omnisend.
Applies to businesses and organizations only — not to messages sent by private individuals.
Coverage: Traficom Order 28 L/2025 covers SMS, MMS, and RCS traffic delivered to Finnish networks, regardless of where the sender is located.
After you register your Sender ID, use that value as your SMS Sender Name in Omnisend. Learn more about SMS Sender Name.
⚠️ Critical Deadlines
4 May 2026 — Traficom Regulation 28 L/2025 enters force. Unauthorized or unregistered Sender IDs are replaced with "Tuntematon" (Unknown) on recipients' devices.
2 November 2026 — Messages with unverified Sender IDs are blocked or shown as "Roskaposti" (Spam).
To stay compliant before 4 May 2026, submit your Sender ID at least 3–4 weeks in advance.
What's Changing
Traficom's Regulation 28 L/2025 (the "Knowing the Sender" rules) requires all Sender IDs to be verifiably linked to your business identity.
Key changes:
All Sender IDs sending to Finnish networks must be either:
Authorized (the operator/aggregator verifies your right to use the ID), or
Registered in Traficom's SMS Sender ID Registry (giving you exclusive rights).
The Sender ID must be clearly linked to your business name, trademark, domain, or lawful business activity.
Operators must block inbound international SMS where the sender appears as a Finnish phone number or alphanumeric Sender ID and rights cannot be verified.
From 4 May 2026, unverified Sender IDs are shown as "Tuntematon" (Unknown).
From 2 November 2026, unverified messages are blocked or labeled "Roskaposti" (Spam).
💡What's an alphanumeric Sender ID? It's the branded name (letters and numbers, up to 11 characters) that appears as the sender of your SMS, for example, "Omnisend" or "YourStore".
Who Is Affected
You are affected if you send A2P (Application-to-Person) SMS messages to Finnish mobile numbers using an alphanumeric Sender ID or a Finnish phone number. This includes:
Promotional campaigns (e.g., sales, offers)
Transactional messages (e.g., order confirmations, shipping updates)
Automated notifications (e.g., abandoned cart reminders, workflow messages)
If you send SMS from a non-Finnish numeric Sender ID, you may still need to comply through your operator's authorization process.
💡 Visit Traficom's official SMS Sender ID page for full regulatory details, and the Sender ID Code of Conduct (PDF) for the operator-level rules.
Sender ID Format Requirements
Whether you authorize or register, your Sender ID must meet these technical limits:
Maximum 11 characters.
Internationally compatible character set: 0–9, a–z, A–Z, and space.
Cannot begin or end with a space, and cannot contain multiple consecutive spaces.
Scandic characters (å, ä, ö) may not render reliably across all routes — check with your provider before relying on them.
Casing is not protected separately — Traficom registration covers all letter-case variations of the same name.
Two Paths to Compliance: Authorization vs Registration
Finland offers two compliance options. Most Omnisend brands use Authorization (via Omnisend). Registration (via Traficom) is optional and gives you exclusive rights to a Sender ID for €200/year.
Details | Authorization (via Omnisend) | Registration (via Traficom) |
Required? | ✅ Yes – Mandatory for everyone | ❌ No – Optional |
Who handles it? | Omnisend submits on your behalf | You apply directly to Traficom |
Exclusive rights? | No – Non-exclusive | Yes – Exclusive rights to the Sender ID |
Cost | Free | €200/year |
Timeline | Up to 2 weeks | 3 months after approval |
Best for | Most merchants | Well-known brands at risk of impersonation |
1. Authorization (mandatory for everyone sending to Finland from 4 May 2026)
Your messaging provider verifies you have a lawful right to use the Sender ID. The Sender ID must clearly relate to your business activity (name, trademark, or domain). Authorization is non-exclusive, as multiple businesses with a legitimate claim could be authorized for the same name, though operators apply the Code of Conduct strictly.
Note: Omnisend handles authorization on your behalf via its certified Finnish-operator partner.
2. Registration ("protection") with Traficom (optional)
You can apply directly to Traficom to register a Sender ID and receive an exclusive right to use it on Finnish networks. Protection takes effect three months after Traficom approves the registration. This is the strongest route and recommended if your brand is at risk of impersonation.
Key constraints if you register:
Sender ID must match your business name in the Finnish Business and Community Information System (YTJ). Spaces/hyphens may be omitted; å/ä → a, ö → o.
Registered IDs cannot be sent via international SMS interfaces after the transition period.
Annual fee: €200, set by the Finnish Ministry of Transport and Communications.
Note: For registration, apply directly via Traficom's registration form. Omnisend does not submit Traficom registration on your behalf.
Required Information for Authorization Through Omnisend
When Omnisend submits your Sender ID for authorization with Finnish operators, you'll need to provide:
Sender ID: The exact alphanumeric name customers will see (e.g., "YourBrand"). It must be clearly linked to your business name, trademark, domain, or lawful activity.
Business Details:
Legal entity name
Business ID (Y-tunnus, if Finnish) or VAT number
Postal and invoicing addresses
Website URL
Business Registration Document: Extract from the Finnish YTJ (for Finnish businesses) or a local equivalent (for international senders). Must show your business name and active status. Accepted formats: PDF or PNG (5 MB max).
Proof of Sender ID Ownership: One of:
Company extract from YTJ
Trademark registration (Finnish or international)
Domain ownership certificate matching the requested Sender ID
Other formal authorization letter
Authorized Representative Details:
Full name
Role/title
Work email address
Government-Issued ID for the Authorized Representative: Passport, driver's license, or national ID card. If submitting a driver's license or ID card, provide both front and back.
Letter of Authorization: Only required if the authorized representative is not listed in the company's YTJ record. Must be signed by someone who is.
Use Case Description: Brief explanation of how you use SMS (e.g., "Promotional campaigns and order updates for e-commerce customers").
Omnisend prefills sample messages and estimated monthly volume when submitting on your behalf.
💡 International senders: Your authorization is submitted through Omnisend's certified telecommunications partner for Finland.
How to Submit Your Sender ID for Authorization
This process is for Sender ID authorization (the default path for most brands). If you want to register with Traficom for exclusive rights, apply directly through Traficom's e-services.
Omnisend handles the operator-level authorization on your behalf. To start:
Step 1. Go to Store Settings → SMS.
Step 2. You'll see a notification to resolve your Sender ID for Finland → Click the link to open the Sender ID registration form.
Step 3. Fill out the form, upload the required documents (listed above), then click Submit.
Once submitted, the status will change to "Submitted". Verification typically takes up to 2 weeks. You'll receive an email notification when your Sender ID is authorized or if there's an issue.
Track Your Registration Status
After submitting the form, track your status under Store Settings → SMS:
Action required: You haven't submitted your registration yet.
Submitted: Your registration is being reviewed by Omnisend's team and the operator partner.
Verified: Your Sender ID is authorized and compliant. You'll get an email confirmation.
Rejected: Your registration wasn't approved. You'll receive an email explaining why. To resubmit, return to Store Settings → SMS and complete the form again with updated information.
FAQ
What's the difference between authorization and registration?
Authorization (via Omnisend): Verifies you have the right to use the Sender ID. Non-exclusive. Required for everyone. Free.
Registration (via Traficom): Gives you exclusive rights to the Sender ID. Optional. Costs €200/year. Takes 3 months to take effect.
Most brands only need authorization.
What if I'm not based in Finland?
You still need to comply if you send to Finnish mobile numbers. Omnisend submits international authorizations through its Finnish-operator partner. If you want exclusive rights to an alphanumeric Sender ID, you can also register directly with Traficom, but your applicant entity must be visible in YTJ or in an equivalent business register.
How long does authorization take?
Verification typically takes up to 2 weeks. Submit at least 3–4 weeks before 4 May 2026 to ensure approval before the deadline.
What happens if I don't authorize or register?
From 4 May 2026, your Sender ID will be replaced with "Tuntematon" ("Unknown") on recipients' devices.
From 2 November 2026, affected messages will be blocked or shown as "Roskaposti" ("Spam") by Finnish operators.
Either outcome will significantly damage trust, open rates, and deliverability.
Will I be notified when my verification status changes?
Yes. You'll receive an email when your Sender ID is authorized or rejected. You can also check the status anytime under Store Settings → SMS.
What happens if my registration is rejected?
You'll receive an email explaining the issue. To resubmit, go to Store Settings → SMS and complete the form again. Make sure all documents are complete and your Sender ID is clearly linked to your registered business name, trademark, or domain.
Can I use multiple Sender IDs?
Yes. But each Sender ID must be authorized separately. Repeat the submission process for each one.
Should I register with Traficom in addition to authorizing through Omnisend?
No, unless you need exclusive rights to your Sender ID. Authorization through Omnisend is enough to send compliantly. Traficom registration is recommended only for well-known brands at risk of impersonation. It costs €200/year and takes 3 months to take effect.
Are MMS and RCS covered too?
Yes. Traficom Order 28 L/2025 applies to SMS, MMS, and RCS traffic delivered to Finnish networks.
💬 Need help? Contact our support team via live chat or email at [email protected].