Developer guide
A familiar prefix can belong to a different network.
Mobile number portability (MNP) lets a customer keep a number when changing carriers. Current carrier lookup resolves the serving network using an appropriate data source. A prefix-based carrier label cannot reliably answer that question after a number has been ported.
Original allocation is not the current carrier
Numbering metadata describes number ranges. In a portability market, a range’s original allocation can differ from the network serving an individual number today. Treat a prefix label and a portability-aware lookup as different data products, with different freshness and coverage requirements.
How QuietPass handles current carrier checks
The optional current_carrier check is the place for serving-network and portability intelligence. Its supplier is not connected yet. Selecting the check currently returns status: "unavailable" with a reason, and no paid network lookup is executed.
{
"phone": "YOUR_VERIFIED_NUMBER",
"checks": ["basic_line_type", "current_carrier"]
}A missing carrier result does not mean the number is invalid, unported, or unreachable. Your application should preserve that uncertainty.
Check country and carrier coverage first
QuietPass’s global scope starts with numbering metadata. It does not imply that every country or carrier has a connected MNP supplier. Call GET /v1/coverage?country=NZ for New Zealand, or use another supported two-letter country code. The catalog currently reports current_carrier: not_connected.
The public coverage page explains how to read empty network lists and unverified coverage. They must not be treated as universal support.
Carrier lookup and SIM-swap checks answer different questions
Carrier lookup asks which network serves a number. A SIM-swap check asks about a recent SIM association change. Neither result substitutes for the other. Start with formatting and validation, then request the additional information your use case needs.
Background: Google libphonenumber FAQ. QuietPass uses the separate JavaScript library libphonenumber-js with full metadata.