A 4G router in a small shop, a MiFi modem in a car, a GPS tracker on a motorbike, a card terminal, a security camera in a plantation, all carry SIM cards. Most never make a call or send a text. But in Indonesia every prepaid SIM must be registered with population data, and that obligation makes no exception for devices.

This is often overlooked because the card is inserted once, tucked inside the device, and forgotten.

Why this is more than a formality

Registration ties each number to one identity. If the internet connection from that number is used for fraud, prohibited content, or other unlawful acts, the trail starts from the recorded identity holder, not from whoever actually used the device.

For shared modems and routers, this means the identity holder shares responsibility for the network they hand out, much like the owner of home Wi-Fi. The general picture is in the guide to Wi-Fi owner responsibility.

Who should own the number

  • Personal devices: use your own identity.
  • Small business devices: the business owner's or a clearly responsible person's identity, not an employee who may leave at any time.
  • Companies with many devices: ask the operator about corporate or postpaid services in the company's name. Management is tidier, and numbers aren't tied to anyone's personal identity.

Because the number of prepaid numbers a person can self-register with one ID is limited per operator, businesses using many modems or trackers soon hit that limit. The corporate route is usually the answer.

Cards sold already "active"

Cards sold already registered, with no buyer details requested, are very convenient to drop into a device. The problem is that the identity used isn't yours, and often it isn't clear whose it is.

  • The number can be blocked at any time if its registration is judged invalid, and the device suddenly goes dead.
  • The number can't be handled at an operator's store because you can't prove ownership, including when the card is lost, damaged, or needs a new size.
  • Someone's identity is being used without their knowledge, and misuse of the number will be traced to them.

Checking numbers in your name

Leaks of population data mean someone's ID number can be used by others to register cards. Check which numbers are registered to your ID through each operator's official service, and report unknown numbers so they are blocked. What to do after a personal data leak is covered in the guide to reporting a personal data leak.

A note for businesses

Keep a simple list: number, operator, the device it sits in, location, identity holder, and validity date. That list saves the day when a card needs renewing, when the employee holding it leaves, and when questions arise about how a number was used.

The technical rules for registration, method, number limits, and documents required, can change. Refer to the latest information from operators and the ministry responsible for communications before handling it at scale.

Conclusion

SIM cards in modems and IoT devices must still be registered, and the identity holder shares responsibility for how they are used. Use your own identity or that of the person responsible for the business, avoid cards already registered to someone else, check the numbers under your ID periodically, and keep a record of every card the business uses.

Frequently asked questions

Does a SIM card for a modem also need registering?

Yes. The registration requirement applies to prepaid cards regardless of the device they sit in, including modems, 4G routers, and IoT devices.

Can I use a card registered with someone else's identity?

Better not. The number is recorded under the identity holder's name, so misuse of the connection is traced to them. Cards sold already registered to unclear identities also risk being blocked.