1. Input normalisation
The tool first removes spaces and other permitted formatting characters. It then checks the length and basic pattern. Passing this step only means that the value has the expected shape.
2. Reading the sections
Next, the tool splits the value into its documented sections. These may include a country calling code, MCC, MNC, TAC, reporting-body code, serial number or check digit.
3. Check-digit validation
If the identifier uses the Luhn algorithm, the tool calculates the check digit and compares it with the final digit supplied. This can catch some typing errors. It does not show that the identifier was officially issued or belongs to a real device.
Cell tower simulation
The calculator uses weighted nonlinear least squares to find the point that most closely matches the supplied tower distances. It works on a metre-based X/Y grid and does not connect to a mobile network.
The uncertainty radius reflects the arrangement of the towers and the uncertainty entered for each measurement. The residual for each tower is the difference between its supplied distance and the distance calculated from the result. Poor measurements or weak tower geometry can produce an inaccurate position even when the calculation succeeds.
4. Reference-data matching
The relevant sections are then compared with records in the site database. A match shows that the source data contains that allocation or association. It may be an old record and does not confirm current use.
5. Interpretation
The labels in a result mean different things:
- Format valid: the value follows the expected pattern.
- Checksum valid: the supplied check digit is correct.
- Allocation found: the database contains a matching record.
- Source verified: the record links back to a named publication.
- Current status unknown: the site has not checked whether it is in use now.
Known limitations
- A ported telephone number may no longer be with the operator that first received the range.
- An MNC can contain two or three digits, so the country code may be needed to read it correctly.
- Public TAC and network records may be incomplete or out of date.
- A valid identifier can be copied, modified or used outside its original context.
- This is an identifier analysis platform, not a live subscriber lookup service.