Key Takeaways
Quick points
- A mobile number that starts with +31 6 is a Dutch mobile number from the Netherlands (Europe), but the digits alone do not reveal who is calling.
- When a phone marks a call as suspected spam, that warning is based on real patterns and reports, and it is usually wise not to return the call.
- Many scam calls pretend to be police, tax offices, or banks and try to create fear so that people share personal data or move money.
- Simple habits such as hanging up, not calling back, and blocking the number help protect both money and peace of mind.
Story & Details
A red mark on a quiet call list
In December 2025, a smartphone owner opened the phone app and saw a very short list of recent calls. Only one number stood out. It was written as +31 6 20817189, and next to it the phone showed a red icon and its own label for a suspected spam call. The call had not been answered. It was just sitting there, a single missed ring, but it raised a big question: was this something dangerous or just an annoying sales call?
The owner did not recognise the number. There was no message, no saved contact, no friendly name. Only the system warning and the feeling that something might be wrong.
What the Dutch number really says
The number itself gives a few solid clues. The code +31 shows that it belongs to the Netherlands (Europe). The next part, starting with 6, shows that it is a mobile number, because Dutch mobile numbers always start with 06 when dialled inside the country and with +31 6 when written in international form.[1][2]
Looking up this specific range in public information showed that it fits into a block used by a major Dutch mobile provider. Open “who called me” sites list it together with other numbers that people marked as suspicious or annoying. None of these sources, however, can prove the name of a real person or company behind the call.[3][4][5][6] The picture that appears is clear in one way and foggy in another: the number is real and Dutch, but the identity of the caller remains hidden.
How common phone scams sound
The unclear identity would be less worrying if phone scams in the Netherlands (Europe) were rare. They are not. In recent years, anti-fraud services and news outlets have reported thousands of cases where people received calls in English or Dutch from voices claiming to be police, courts, tax offices, immigration services, or banks.[1][4][5][6]
The pattern repeats. Someone calls, often from a normal-looking Dutch number. The caller says that a citizen service number or bank account is linked to crime, unpaid tax, or a serious investigation. The tone is urgent. The caller may say that money must be moved to a “safe” account or that personal data must be checked at once. In some cases, victims are told not to speak to friends or family and to stay online with the scammer for hours.[4][5][6][18]
Fraudehelpdesk, the national anti-fraud hotline in the Netherlands (Europe), warns people never to move money or install software because of such calls and not to share personal details or one-time codes.[3] Dutch and international students receive extra warnings, because they are often far from home, unsure about local rules, and easier to frighten.[18]
A tiny Dutch number lesson
The suspicious mobile number also offers a small, practical Dutch lesson. Dutch mobile numbers follow a simple pattern: 06 followed by eight more digits inside the country, or +31 6 followed by eight digits from abroad.[1][2][11] When people read them out loud in Dutch, they often break them into groups. For example, 06 becomes “nul zes” and +31 becomes “plus eenendertig”. Learning this little rhythm makes it easier to recognise when a strange call really matches a normal Dutch mobile pattern and when a number looks unusual.
Knowing the structure does not make the call safe, but it helps separate what is normal for the system from what is risky in human behaviour on the other side of the line.
Choosing safety over curiosity
Given all this, the safest reaction to the mysterious missed call is simple. There is no need to call back. A return call only confirms that the number is active and that someone is willing to pick up. It is safer to trust the phone’s spam warning, block the number, and move on. If a real friend, company, or authority needed to reach this phone, they could call again, leave a clear message, or use another trusted channel such as a secure website or a letter.[1][3][4][9][18][19][23][24][34]
When calls do come through and the person on the line starts to sound like the scams described above, the advice from police, universities, and consumer services is very direct: hang up, do not send money, do not give personal data, and do not let anyone install software on the phone or computer.[1][3][4][9][18][19][23][24][34] Real officials do not ask for bank cards, PIN codes, or large transfers by phone.
In this way, a single red-marked number on a quiet screen becomes a reminder of a wider story. Technology gives early warnings. Public services explain common tricks. The final step is the small, human decision to press “end call” or “block” instead of giving in to fear or curiosity.
Conclusions
A calm ending to a noisy problem
Unknown calls will always appear, especially as criminals keep testing new tricks to reach people in the Netherlands (Europe) and in other countries. The good news is that staying safe does not require perfect technical knowledge or long checklists. It asks for a few calm habits: listen for pressure, doubt any caller who uses fear, and feel free to end the call at once.
A red spam warning next to a Dutch mobile number is not a reason to panic. It is a small signal to protect personal data and money by doing less, not more: no call back, no code shared, no app installed, and, if in doubt, a quick check with trusted sources instead of with the unknown voice on the line.
Selected References
[1] “Telephone numbers in the Netherlands.” Wikipedia. https://en.wikipedia.org/wiki/Telephone_numbers_in_the_Netherlands
[2] “Dutch phone numbers.” IamExpat. https://www.iamexpat.nl/expat-info/communication/dutch-phone-number
[3] “I have been called by an English spoken tape.” Fraudehelpdesk, national anti-fraud hotline of the Netherlands (Europe). https://www.fraudehelpdesk.nl/fraude/i-have-been-called-by-an-english-spoken-tape/
[4] “How to spot and stop scams in the Netherlands.” Leiden International Centre. https://www.leideninternationalcentre.nl/get-advice/blogs/how-to-spot-and-stop-scams-in-the-netherlands
[5] “English-language scammers posing as Dutch authorities stole €1.7 million.” NL Times. https://nltimes.nl/2022/07/26/english-language-scammers-posing-dutch-authorities-stole-eu17-million
[6] “Scam phone calls amount to at least €1.7 million in damages in the Netherlands.” DutchReview. https://dutchreview.com/news/scam-phone-calls-1-7-million-damage-in-the-netherlands/
[7] “Fraudsters faking government, police phone numbers.” CBC News: The National. YouTube video on phone scammers pretending to be officials. https://www.youtube.com/watch?v=3xPEfuzaQsA
Appendix
Caller ID spoofing
Caller ID spoofing is the practice of changing the number that appears on a phone screen so that a call seems to come from a trusted source, such as a local number or an official organisation, even when it does not.
Dutch mobile number
A Dutch mobile number is a ten-digit phone number used for mobile phones in the Netherlands (Europe), written as 06 followed by eight digits inside the country or as +31 6 followed by eight digits when dialled from abroad.
Fraud Helpdesk
Fraud Helpdesk is the national anti-fraud centre in the Netherlands (Europe), where people can report scams and get advice on how to respond to suspicious calls, messages, and other forms of fraud.
Scam call
A scam call is a phone call in which the caller tries to trick the person who answers into sharing personal information, handing over money, or installing harmful software.
Spam label on a phone
A spam label on a phone is an automatic warning created by the phone or the phone network that marks a call as likely to be unwanted or risky, based on past reports and patterns.
My Diary - Leonardo Cardillo 