A ServiceTag is much simpler than many people expect. The tag itself does not connect to the internet. It has no battery, cellular radio, Wi-Fi, Bluetooth, GPS or account, and it cannot phone home, report its location or transmit anything by itself.
The phone powers the interaction
The tag sleeps until an NFC reader comes very close. The phone's NFC field supplies just enough energy for the tag to wake, answer and go quiet again. That is why NFC only works at a few centimeters, and why the tag is not broadcasting like a Bluetooth tracker. With no battery to run down, a tag can stay on equipment for years, subject only to wear and the limits of the tag you chose.
What is on a ServiceTagPro tag
ServiceTagPro tags are designed to carry two small things:
- a web address on servicetagnfc.com that ends in a random code. The code is not derived from you, your address or the equipment, and it never changes;
- a ServiceTag marker with an opaque identifier, so ServiceTag apps recognize the tag.
The tag's public message does not contain names, email addresses, accounts, street addresses, the equipment's make, model or serial number, its service history, documents, photos, a service company's business information, passwords or keys. A branded label may separately show a company's public logo and phone number in print.
What happens when someone scans it
Their phone opens the tag's web address, with no app and no account needed. The page shows only what the equipment's manager chose to show for that spot, such as “Unit 140” or a hotel room number, and, where the building offers it, a way to report a problem. By default it shows nothing about the place at all. It never shows the equipment's details or history, anyone's name, a home's address or other units. Private equipment details require verified, authorized access. Owners and service teams sign in; the planned guest portal will also let an invited contractor verify their email and see only the history the customer shares. Copying the tag, or sharing its link, gives nobody access.
Reporting a problem needs no account, but it always needs proof: a one-time code sent to the phone number or email the building or service company already has on record, or a tap of a secure tag. A copied link on its own cannot be used to file anything.
Like any website, servicetagnfc.com receives the request when a phone opens that address: the tag's code and the usual technical details of a web visit. The tag itself sends nothing; the phone's browser does, and only when someone scans it. Tag pages are never cached and never indexed by search engines.
- The tag: a web address and an identifier
- A public page showing only what the building chose to show
- Optional sign-in, for owners and service teams
- A check of the person's current access
- Only the part of the record their relationship allows
Can someone tell it is a ServiceTag?
Yes. The web address and the marker say so, and a generic NFC app can also show the chip's own technical details. None of that reveals the equipment's record or anything about you.
Can someone guess a tag's web address?
No. The code at the end of each address is 128 bits chosen at random by a cryptographic generator, with no pattern and no link to the tag, the equipment or you. Even guessing at millions of addresses a second for billions of years would not be expected to find a single real tag. And a tag found any other way, by being near it or being sent its link, shows only what the building chose to show, and nothing can be done from it without proof.
Can the tag track me or my equipment?
No. A passive NFC tag has no GPS, no internet connection and no radio of its own. It does not broadcast, cannot report when or where it was moved, and answers only when a reader is brought very close.
An identifier, not a key
Assume that anyone close enough with a phone can read a tag. That is fine, because a ServiceTag is an identifier, not a password: holding the tag is not the same as being someone, and being someone is not the same as having access. ServiceTagPro tags are designed to be permanently locked once written, so nobody can overwrite them; a damaged or compromised tag is replaced with a new one and retired.
When equipment is retired
When equipment is removed, replaced or thrown away, its tag is retired with it. Scanning a retired tag shows only that it is no longer in service; nothing can be reported or requested through it.
Higher-security tags, on the roadmap
Ordinary ServiceTags are identifiers, and that is enough for most equipment. For sites that need more assurance, we are evaluating optional higher-security tags:
- authenticated tags, whose every response carries a cryptographic signature ServiceTagPro can verify, so a genuine scan can be told apart from a copied link;
- tamper-aware labels, which can show that a seal was broken;
- simple readings taken at the moment of a scan, where a tag is built with a suitable sensor.
For people with no contact on record, such as hotel guests, problem reports are designed to be accepted only from authenticated tags, so a link copied from a tag cannot be used to file them.
These are being researched and planned; they are not available today. Even then, a verified tag response is evidence, not a key: it does not prove who scanned the tag, that they stood at the equipment or that work was done, and access will still come only from authorization.
Compared with the standalone ServiceTag app
Tags written by the open-source ServiceTag app carry no web address. They open a record in the app's own database on the owner's phone and never contact a server. ServiceTagPro adds the web address so that any phone can reach the right page without an app.