SMS marketing in Sweden: consent, NIX and the existing-customer question
Marknadsföringslagen's opt-in rule, why NIX-Telefon doesn't save your SMS campaign, and how the existing-customer exception should be read for text messages.
Honesty first: this is practical guidance, not legal advice. Marketing law changes and edge cases are real — when in doubt, ask a lawyer, and always check current operator requirements before a big campaign.
Sweden's rules live in the Marketing Act (marknadsföringslagen, 2008:486), supervised by the Consumer Agency (Konsumentverket). For electronic direct marketing to consumers the starting point is the same as everywhere in the EU: opt-in consent before you send.
The main rule
Unsolicited marketing via email or SMS to individuals requires prior consent — GDPR-grade: freely given, specific, informed, documented. Sweden's marketing culture is less litigious than Denmark's, but Konsumentverket does act on complaint patterns, and mobile spam complaints are exactly the pattern that triggers reviews.
NIX-Telefon is about calls — not SMS
A recurring Swedish misunderstanding: "we washed the list against NIX, so we're fine." NIX-Telefon is a do-not-call registry for telemarketing calls. It has no bearing on SMS marketing: not being in NIX doesn't create consent, and being in NIX doesn't add restrictions beyond the ones that already apply. For SMS the question is only ever: do you have documented consent (or a valid existing-customer basis)?
The existing-customer exception, read carefully
The Act allows contacting existing customers about your own, similar products using contact details obtained in connection with a sale — if the customer was informed and can opt out easily, in every message. The statutory language grew up around email, and the cautious reading for SMS is exactly that: cautious. If you want to build SMS marketing on the existing-customer basis, document the assessment, keep it strictly to similar products, and make opt-out effortless. The genuinely safe route remains explicit consent — a double opt-in form collects it in one step and logs the evidence.
Practical layer
- Alphanumeric senders (max 11 characters) work in Sweden without a registration scheme.
- STOP handling: Swedish recipients expect "svara STOPP" — WeZend intercepts STOP/STOPP keywords automatically and writes the suppression instantly.
- Quiet hours: no statutory night-time ban for SMS, but 21:00–09:00 sends are where complaints come from. A platform-wide quiet-hours window costs you nothing and buys goodwill.
The Swedish checklist
- Documented opt-in for consumer SMS marketing; treat the existing-customer route as a lawyer-reviewed exception, not a default.
- Don't confuse NIX with SMS compliance in either direction.
- STOPP respected instantly; sender identified in every message.
- Consent records exportable — the platform keeps them on the contact automatically.