SIM Swap Scams in Portugal
Criminals port Portuguese mobile numbers to intercept SMS banking OTPs and drain EUR from Multibanco and online banking accounts.
Part of: SIM Swap Scams
Last reviewed: 1 June 2026
Portugal's banking sector uses SMS OTPs heavily for online transaction authorisation. SIM-swap fraud exploits this by convincing NOS, MEO, or Vodafone Portugal staff to transfer a victim's number to a scammer-controlled SIM, enabling interception of banking authentication codes.
Banco de Portugal and CNCS have flagged SIM-swap fraud as a growing threat to Portuguese e-banking security. MB WAY, which is linked to mobile numbers, is especially vulnerable once a SIM swap is complete.
How this scam works on Portugal
Attackers harvest victim personal data through phishing or data breaches, then visit or call a Portuguese carrier impersonating the victim to request a new SIM card. Once the port completes, the victim loses signal.
The attacker intercepts SMS OTPs from MB WAY, online banking, and investment platform apps, and initiates EUR transfers. MB WAY transfers can be completed and irreversible within minutes.
Some variants first use phishing to obtain partial banking credentials, then combine with SIM swap to bypass the remaining SMS OTP barrier.
Common red flags
- Your Portuguese phone loses signal unexpectedly
- Carrier SMS alerts you to a SIM change you did not request
- MB WAY or banking OTPs arrive for transactions you did not initiate
- Bank alerts you to a login or transaction from an unrecognised device
- Carrier confirms a recent SIM swap you do not authorise
How to protect yourself
- Add a SIM-lock PIN at your NOS, MEO, or Vodafone Portugal store or app
- Switch from SMS OTP to app-based authentication where your Portuguese bank allows
- Set low daily transfer limits on your Portuguese online banking
- Contact your carrier and bank immediately if you lose signal
- Enable MB WAY and banking transaction alerts
- Report to CNCS at cncs.gov.pt if a SIM swap is confirmed
How to report it
- Call your carrier's fraud line immediately for an emergency port-freeze
- Contact your bank's 24-hour fraud line
- Report to CNCS at cncs.gov.pt/reportar and Polícia Judiciária
Frequently asked questions
What's the fastest way to stop a SIM-swap attack in progress on my Portuguese number?
Call your carrier's fraud line immediately to request an emergency port-freeze, and contact your bank in parallel to flag your accounts, since attackers often move within minutes of completing the swap.
Can I switch away from SMS-based authentication for MB WAY or Portuguese banking?
Where your bank offers app-based or biometric authentication instead of SMS OTP, switching may reduce your exposure to SIM-swap fraud — check your bank's security settings or ask their support team what alternatives are available.
How would I even know my Portuguese SIM has been swapped before losing money?
The clearest early sign is your phone suddenly losing all signal in an area with normal coverage, sometimes alongside a carrier SMS confirming a SIM change you didn't request. Treat unexpected signal loss as an emergency, not an inconvenience.
Is MB WAY especially vulnerable to SIM-swap attacks?
Yes. MB WAY is tied to your mobile number, so a completed SIM swap gives attackers access to receive MB WAY authentication codes. Adding a SIM PIN is the most effective mitigation.