In some cases, the library cannot tell if the leading digits of a phone number are intended to be the country calling code, or the start of the national significant number.
This affects primarily German and Indonesian phone numbers, where country calling code (49 and 62 respectively) is also a valid area code, and numbers of variable lengths are valid. The leading digits will only be interpreted as a country calling code if the number is not already considered a possible number for the region provided when parsing.
If you know that your numbers are always in the form <country calling code><national significant number>, it is safe to put a "+" in front to indicate this to the library.
When parsing, the library does its best to extract a phone number out of the given input string. It looks for the phone number in the provided text; it doesn't aim to verify whether the string is only a phone number.
If the input looks like a vanity number to the library, parse() assumes this
is intentional and converts alpha characters to digits. Please read the
documentation for PhoneNumber parse(String, String) in
PhoneNumberUtil
for details. Also see Iterable<PhoneNumberMatch> findNumbers(String, String).
Some examples:
-
+1 412 535 abcdis parsed the same as+1 412 535 2223. -
If someone mistypes and adds an extra alpha character in the middle, then the library assumes this was a mistake and fixes it. E.g. the extra
cin+1 412 535 c0000is ignored, and this is parsed the same as+1 412 535 0000. -
If someone mistypes and replaces a digit in the middle with an alpha character, and the remaining characters do not make up a valid number, this alpha character is not converted and the resulting number is invalid, e.g. with
+1 412 535 c000.
Usually, when parsing, we remove a country's national or trunk prefix, so we can store a normalized form of the number. This is usually, but not always, a leading zero. In some situations, we don't remove this, but instead keep it as part of the national number:
- If a country does not use a national prefix, or does not use one anymore, we don't remove a leading zero, since then if the user wanted to format the number we would never know to prefix it with this leading zero.
- If the leading zero is not a national prefix but is needed for dialling from abroad (e.g. in the case of Italy) it is stored in the proto, not removed as a national prefix.
- If the number is too short to be a valid phone number in this country, we do
not remove the national prefix. For instance, although
0is a national prefix in Australia, we do not remove it from the number000which is the emergency number; if we did we would not know that it needs a0re-added when formatting since other short-codes do not, and we would be irreparably changing the phone number.
00 is not an international prefix (IDD) in every region, so it's not
equivalent to +.
For example, if parsing 0015417540000 as if dialled from the
US,
the national number is 15417540000 because 00 is not an international prefix
in the US.
Ascension Island, however, does have 00 as an international prefix, so 00
there works the same as + and 0015417540000 as if dialled from
AC
gives 5417540000 for the national number.
You can try the demo for more regions.
Also see internationalPrefix in
resources/PhoneNumberMetadata.xml.
To understand the behavior of functions, please refer to the documentation in
the Dart header files. For example, see isPossibleNumberWithReason in
PhoneNumberUtil.
Short numbers are out of scope of
PhoneNumberUtil.
For short numbers, use
ShortNumberInfo.
Our phone number library can tell that a number range is valid when there is sufficient official documentation, with some latency after this fact is brought to our attention via issue reports or notifications (see below for more information on where our metadata comes from). A valid number range is one from which numbers can be freely assigned by carriers to users.
Do not rely on libphonenumber to determine whether numbers are currently assigned to a specific user and reachable. Some products (e.g. Google 2-step verification) do this with a verification step e.g. by sending an SMS or placing an automated phone call with a verification code). This is not technically feasible without such a verification step given the complicated international world we live in, with varying standardization practices in different regions.
Not necessarily.
- In some countries extra digits at the end are ignored. For example, dialling
1800 MICROSOFTin the US connects to+1 (800) MIC-ROSO. - During renumbering transitions, e.g. when all numbers are getting an extra
9added to the front, some operators will "fix" old numbers long after they're no longer working for the majority. - Numbers that are only locally-diallable e.g. a 7-digit number dialled in the US are not valid, because without the rest of the number it is impossible for the library to canonicalize this.
Rarely! Many people have phone numbers that do not belong to the country they live in. This applies particularly to mobile numbers, but may also be true for VoIP numbers etc. Note also that the regions your application supports may not be the same as the regions we support. For example, the Channel Islands such as "Jersey" have their own region code - JE. If you allow these users to sign up as a British user ("GB"), their phone numbers will not be considered valid for the region "JE".
One use-case where this method may be useful is if you want to see if a
FIXED_LINE number for a business matches the country it is in, to try and spot
data errors.
This could be due to number simplification. In order to keep the size of the XML files to a reasonable level, it's necessary in some regions (e.g. "DE" or "AT") to simplify number ranges. This results in a relatively small amount of false positive numbers (i.e. numbers that should be reported as invalid, but which are now shown as valid).
This issue here is that (for simplicity) only the number validity information is simplified; the formatting information in the XML (leading digits) retains its full accuracy and so doesn't cover these numbers.
Note that while it is probably possible to address this and expand the format information to cover these numbers as well, it's a rather non-trivial task (since the leading digits must not be over simplified so as to capture other valid ranges with different formats). Note that this also applies to attributes like "national only" or geocoding information.
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.
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 way.
The ability to keep your mobile phone number when changing carriers. To see whether a region supports mobile number portability use isMobileNumberPortableRegion.
Not all regions support mobile number portability. For those that don't, we return the carrier when available. For those that do, we return the original carrier for the supplied number.
libphonenumber does not support M2M numbers in general, but only in one exception case where in Netherlands 097X M2M numbers are used as regular mobile phone numbers.
The reason for Libphonenumber to not provide M2M support is related to the lack of standardization and the need for a new Util API (not in radar for the time being).
We don't require that a number to be supported by the library has a human at the other end since we already accept premium rate services and they might go to an automated system instead. But to date we only accept ranges that a human might call or send an SMS to.
M2M numbers would violate this assumption and we'd have to evaluate the consequences for existing APIs and clients if M2M numbers would be considered valid by the library. Clients of libphonenumber expect mobile and fixed-line numbers to have certain affordances, such as: Reachable for voice calls (and for mobile also SMS) as well as assuming standard cost. This expectation is broken by the lack of M2M standardization today.
Many people use this library for formatting the numbers of their contacts, for allowing people to sign up for services, for working out how to dial someone in a different country, for working out what kind of cost might be associated with a number in an advert, etc. We don't think the lack of M2M support hinders any of those use-case, but we might be wrong.
At the moment Libphonenumber can only support phone numbers that can be dialled by us, not by machines. If you found any humanly diallable M2M numbers that library is not supporting, please raise an issue here with all authoritative and specific documentation such as government sources, which have varied definitions.
Official authority has explicitly stated that this range “should be made accessible, just like other, regular number series from the Netherlands” and that “you can set up a voice and SMS connection towards prefix +31-97 in the same way as you have done already with the +31-6 series.[...] you should enable your systems for voice telephony for the numbers in the +31-97 series”. This means, however, that there might be cases where the library would categorise a number as a valid mobile number, but in reality, the particular number is used as pure M2M, is not SMS or voice-enabled. There is not much we can do from our side about this, since we always follow official guidelines.
Therefore, clients should be aware that there is possibility of false positives in NL MOBILE category. The library will continue to not support M2M numbers in general.
There are some numbers that only work for the subscribers of certain operators for special operator-specific services. These differ from carrierSpecific since they're not shortcodes. We don't support these numbers due to their limited use scope, few examples (only the area code 700 in the US), and lack of authoritative evidence.
Until there are more examples with authoritative evidence and a proposal on how the library should handle these numbers, we won't be able to support these similar to our prerequisites for supporting M2M.
Please see this issue for more context, and file a new issue if you're able to provide more information than this.
We support parsing and storing numbers from a minimum length of two digits to a maximum length of 17 digits currently (excluding country calling code). The ITU standard says the national significant number should not be longer than fifteen digits, but empirically this has been proven not to be followed by all countries.
No, phone number formatting is country-specific and language-independent. E.g. formatting a US number in a French way (e.g. the way a France number is formatted) for a French user is undefined and wrong.
It is true that in some countries phone numbers are typically written using native, not ASCII, digits; our phone number library supports parsing these but doesn't support it at formatting time at the moment.
The formatting within a country changes sparingly, but may be announced explicitly or noted implicitly in a national numbering plan update that introduces a new number length, number type, or other significant change. This may include the grouping and punctuation used (e.g. parentheses versus hyphens).
In the event of lack of evidence and/or enforcement by a central government regulatory or telecommunication authority, we'll stick with the status quo since the community prefers to bias towards stability and avoid flip-flopping between formats over time. If the silent majority becomes vocal to support new formatting with authoritative evidence, then we'll collaborate with community stakeholders on a transition.
An example of this is the shift from using parentheses to hyphens to separate area codes within North America. Hyphens may indicate that the area code is optional in local circumstances, but this is shifting to become mandatory in areas that have had more area code splits. However, the usage of parentheses persists and both methods are acceptable.
See issue #1996 for some additional discussion.
If we don't think we can guarantee that the number is diallable from the user's mobile phone, we won't return anything. This means that for numbers that we don't think are internationally diallable, if the user is outside the country we will return an empty string. Similarly, in Brazil a carrier code is essential for dialling long-distance domestically. If none has been provided at parsing time then we will return an empty string. If you get an empty string and are okay providing a number that may not be diallable, you can call another of our formatting numbers instead.
We use the word "metadata" to refer to all information about phone numbering in a particular country - what the country code, international and national dialling prefixes are, what carrier codes are operational, which phone numbers are possible or valid for a particular country, how to optimally format them, which prefixes represent a particular geographical area, etc.
In theory, phone numbering plans are all supposed to be administered through the ITU. Many countries' phone numbering plans may be found on the ITU website.
We receive automatic notifications when a new ITU plan has been filed, which may or may not be before it comes into effect.
Not every country files their numbering plans with the ITU nor are the plans filed with ITU always up to date. In some countries, the numbering plans are directly handled by a government authority, while in others, most of the work is done by telecom companies (the government's role being only to distribute ranges at the prefix level, with the actual partitioning within the prefix done by the telecom).
A large part of the data in PhoneNumberMetadata.xml comes from the ITU
documents, but because they're sometimes insufficient, we also include data from
other sources, including user bug reports, telecom company home pages and
government telecommunication authorities.
There is no RFC indicating where the data comes from, or what format they're in.
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!
Certain countries' mobile and/or fixed line ranges may overlap or too granular, which may make accurate identification impossible. Eg: Argentina and Mexico. We tried incorporating such granular data (prefix of 7 digit for a 10 digit number). However, due to very high maintainance to keep the data fresh and also leading to significant increase in metadata size, we are supporting ranges/prefixes only at higher level. More details in Argentina and Mexico triaged issues.
@Argentina, 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!
We rely on these additional and explicit context such as a mobile prefix to
correctly identify the phone number type (rather than returning FIXED_LINE_OR_MOBILE
in ambiguous cases).
Moreover, Argentina has 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.
We are aware of these issues but fixing them is not trivial. In the meantime, we recommend the following workarounds to support affected users.
- If you know an Argentina number is mobile (e.g. if you're doing signups with
device numbers or will send them an SMS verification code), follow these steps:
- For raw input strings:
- Parse a raw input string into a
PhoneNumberand follow the next instructions forPhoneNumberobjects.
- Parse a raw input string into a
- For
PhoneNumberobjects:- Check that the library validates a
PhoneNumberas mobile, by callinggetNumberType; - If not, format it in national format and prepend a
9 - Parse the modified string and if the library validates it as mobile,
accept the resulting
PhoneNumberas canonical.
- Check that the library validates a
- For raw input strings:
- Consider prompting for type (mobile or not) in the phone number input UI.
IMPORTANT: Do not add a leading 9 for displaying or formatting the numbers. Depending on the use case, other tokens may be needed. The library will do the right thing if the phone number object is as intended.
@Mexico,
Mexico used to have such additional prefixes (1, 02, 045, ...) for dialling
mobile numbers internationally, fixed-line to mobile nationally.. As these
dialling patterns were deprecated, we have continued to maintain mobile and
fixed-line ranges at higher level, returning type as FIXED_LINE_OR_MOBILE
Though library has stopped supporting below older dialling codes in the canonical form and formatting results, we are lenient in parsing the number, i.e removing all older codes.
- 1 -> in E.164 international diallings
- 01, 02, 044 and 045 -> for local/national diallings
This is because we found the older dialling codes supported even after deprecation period, so we decided to support them for longer time. However, we will stop this as part of this issue. More details there.
We only support a country if:
- The country has a single country calling code. For instance, Kosovo (XK) has been using three different country codes until 2017 - those of Serbia, Monaco and Slovenia. The relevant numbers will be marked as valid, but as belonging to Serbia, Monaco or Slovenia respectively. When Kosovo starts using its own country calling code of 383 it will be added to the metadata by itself. Similarly, Antarctica doesn't use its assigned country calling code of 672 - instead the bases belonging to different countries have different solutions. For example, Scott Base, belonging to New Zealand, has an area code that is part of the New Zealand phone number plan, and we support those numbers as valid numbers for NZ.
- The country still exists. For example, Yugoslavia (YU), Serbia and Montenegro (CS) and Netherlands Antilles (AN) have been dissolved and no longer exist as political entities so we do not support them.
- The country has some phone numbers in use that can be ascribed to it. For instance, Pitcairn Island has only around thirty inhabitants and they use satellite phones, so there is no numbering plan for Pitcairn Island. Similarly, Bouvet Island is an uninhabited Antarctic volcanic island with no telephone country code and no telephone connection, so we will not support it.
- It has an assigned region code. For instance, previously Kosovo did not have a region code assigned to it, so we could not support it until it was assigned XK by CLDR.
We support non-geographical entities that have been assigned country calling codes by the ITU where a numbering plan is available, e.g. "800" (International Freephone Service) and 870 (Inmarsat SNAC). However we do not support country calling codes that are only "reserved", or that no data is available for (namely 388 - listed as "Group of countries, shared code" and 991 - listed as "Trial of a proposed new international telecommunication public correspondence service, shared code".)
Although some numbers beginning with "001 803" or "007 803" do work in Indonesia to reach toll-free endpoints, these numbers are hard to support because they overlap with the international dialling prefix for Indonesia (IDD). It seems that since 803 is unassigned and not a valid country code, some local tel-companies in Indonesia hijack 803 and redirect it to their own services.
We have also found evidence that reaching some "00x 803" numbers cost local or national tariff, rather than the call being toll-free.
These numbers are not diallable from any other country using their IDD,
and it's unclear whether all carriers in Indonesia support them. If we ever
supported them, they would have to be added to the noInternationalDialling
section, and it is likely some changes in the parsing code would have to be
made to interpret the "00x" as something other than an IDD: this could have
undesirable side-effects when parsing other numbers.
We supply example numbers as part of the library API. While we aim to have numbers that are either explicitly allocated by the country as a test number, or look fictitious (e.g. 1234567) we also need these numbers to validate correctly. This means we sometimes have numbers that do connect to a real person.
If we by chance have actually listed your real number and would like it removed, please report this through Google's new Issue Tracker. Only our internal team will have access to your identity (whereas GitHub usernames are public).
Why can the smallest digits of parsed numbers that are very long be incorrect when parsing in Javascript?
Eg: National number of 90018408059449387, region: JP is parsed as
90018408059449390. Reason: When the provided number is more than the max
limit of JavaScript Number type - 2^53, JS starts rounding the value.
libphonenumber cannot do anything better here. More details mentioned in this issue.