diff --git a/FAQ.md b/FAQ.md index 4fb6e8680..695a0dbc9 100644 --- a/FAQ.md +++ b/FAQ.md @@ -72,11 +72,11 @@ data errors. ### What types of phone numbers can SMSs be sent to? -SMSs can be sent to `TYPE_MOBILE` or `TYPE_FIXED_LINE_OR_MOBILE` numbers. However, +SMSs can be sent to `MOBILE` or `FIXED_LINE_OR_MOBILE` numbers. However, in some countries it is possible to configure other types, such as normal land-lines, to receive SMSs. -### Why did I get `TYPE_FIXED_LINE_OR_MOBILE` as the type of my phone number? +### Why did I get `FIXED_LINE_OR_MOBILE` as the type of my phone number? Some number ranges are explicitly defined as being for fixed-line or mobile phones. We even represent ranges defined as being "Mostly land-line" in this @@ -208,6 +208,32 @@ We'd love to consume machine-readable numbering plan data (assigned ranges, carrier & geo mappings). If you can connect us with partners in the industry to achieve this, please do so. Thanks! +### Why is this number from Argentina (AR) or Mexico (MX) not identified as the right number type? + +Certain countries' mobile and/or fixed line ranges may overlap, which may make +accurate identification impossible without additional and explicit context +such as a mobile prefix. We rely on this prefix being present to correctly identify +the phone number type (rather than returning ['FIXED_LINE_OR_MOBILE'](#fixed_line_or_mobile) +in ambiguous cases) until our metadata can be fine-grained enough to detect when a user has omitted it. + +For example, when calling a mobile line from a fixed line in Argentina, +you need to dial 15 before the subscriber number, or 9 if you're calling +from another country. Without these additional digits, your call may not +connect at all! + +Similarly, Mexico has different mobile prefixes needed when calling from a fixed +line such as 044 when calling locally, 045 when calling from another state, and +1 when dialing from another country. + +Moreover, these countries have different possible lengths for area codes and subscriber +numbers depending on the city, which further complicate matters (e.g. Buenos Aires is 11 +followed by eight digits, but Río Gallegos is 2966 followed by six digits). + +Despite all the aforementioned complexity, users may not provide their phone number +with all the additional context unless explicitly asked. For instance, +since SMS messages can be sent in Argentina from a mobile phone without a prefix, +the user may not supply the mobile prefix. + ### Why are Bouvet Island (BV), Pitcairn Island (PN), Antarctica (AQ) etc. not supported? We only support a country if: