I have a form that asks for the customer's phone number number. The customers are international and not limited to the U.S. and Canada.

Does anyone have any best practices on how to lay out (and label) the form fields?

  • 1
    Can you give an example. For instance are you needing the customer to supply you with country code, and main number including State code? Let's say a certain person has the number in the US: 202-456-1414 - or in Canada 613-941-6900 - are you wanting to collect the country as well as the number? Jun 25, 2011 at 15:49
  • It's just that as far as I can see the area codes do not overlap so you can determine country from area code ( areacodelocations.info/areacodelist.html ) Jun 25, 2011 at 15:57
  • I didn't phrase the question as clearly as I should have. The customers are not limited to US and Canada is the issue so I have to ask them for their country code somehow. Jun 25, 2011 at 16:36
  • hah! - For other's reading this, the edited change was from 'and limited' to 'and NOT limited'! Jun 25, 2011 at 17:30
  • For those that are wondering - the solution that was implemented and fit the context of my task was a drop down list of countries followed by a single textbox for the phone number (and another for extension in the case of businesses). Validation-wise was pretty much digits, hyphens, and spaces with an open format. Jun 27, 2011 at 16:43

5 Answers 5


I'm afraid this question is a bit unclear to me.

Are you just asking for the customer's international phone code, not the number itself (a 'phone number number')?

It would probably make more sense just to ask which country the customer resided in. That way, your customer doesn't have to remember which code relates to which nation.

  • The scenario I have is allowing customers to add and update their phone number. International phone numbers are an option so having a way to change the country from U.S. is important. I really like your suggestion of asking for country instead of the code. It's a very clear field at that point. Jun 25, 2011 at 16:03
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    Actually, most people know their own country's telephone code, especially when they are used to dealing with other countries... Jun 26, 2011 at 8:14
  • I totally disagree (sorry) with Marjan, since my own experience is that many, possibly the majority of people, don't know their country code. Maybe most technically-adept, or internationally travelled, or whatever - sure. Why am I saying this? I am finding as I personally also try and figure this out, that people using phones NOT BASED in their "home country" is not necessarily huge, but it is another concern. In trying to come up with as close to a 100% solution as I can, I'm seriously debating asking for their PHONE's Home Country, and continuing to use IPLookup to get "their country"...
    – AMM
    Nov 14, 2014 at 21:19
  • (continued)....... even as I know that IPLookup of their country is subject to it's own problems (could be traveling, IP could be misleading, etc ad nauseum). Given THAT fact, I'm tending toward this: Phone: ____________ .... Country: ____________ ... (after they type in their Phone and submit... if the leading digits do not match their Country, popup-ask them to verify if that is the case ... if confirmed, use their apparent country code to populate a "Phone Country" field. Frustrating. How dare people have phones from a country that don't live in primarily!
    – AMM
    Nov 14, 2014 at 21:22

While I agree with @jbreckmckye to ask for the country, not the country's telephone number as that can be inferred from the country, I do think that most people know the telephone number of their country and can spit it out at will.

That said, I would not split the telephone number in separate fields at all.

I would ask for the for the country in a separate field like @jbreckmckye because the country also dictates how an address should be laid out (some countries have the postal code before the city, others have it after the city or even completely separate).

I would allow the telephone number to be entered in a free format. It may restrict what you can do with it "automatically" (or require a very good parser to enable automatic processing). More importantly though, it will allow users to enter their phone number in the way they are used to entering phone numbers instead of forcing them to conform to a format they may not be familiar with.

As a suggestion you could give an example of an international phone number adjacent to the telephone number field.

+31 (0)30 1234567

This example also shows the way international phone numbers are/should be formatted to take care of the dropped zero @PhillipW mentions.

In general terms the international format for a telephone number actually is

+<country> [(0)]<area> <subscriber>


  • + signifies the international exit code which differs per country;
  • the (0) is optional (indicated by the square brackets) and signifies the zero of the area code which you need to drop when dialing from outside of the country (indicated by the brackets) but need to dial if you are in the country.
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    So in other words: just ask them for their country, and ask them for their phone number, and ignore the first zero if they enter one. It may confuse users if you show an example of an international phone number, since you're not asking them to enter one. Jun 27, 2011 at 0:42
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    Good thinking about needing the country to layout / label address! Jul 4, 2011 at 18:26
  • A bit of trivia: when I worked for a global company we at some point had to collect lots of contact numbers from around the globe: people in 'little' countries (such as the Netherlands) supplied full international numbers, respondents in big countries ( such as the USA) didn't.
    – PhillipW
    Oct 23, 2020 at 18:31

Be aware that you're going to run into fun and games with the 'dropped' first zero issue.

Eg the correct format for London England is +44 20 X XXX XXXX

However if you just ask for the country and the number you'll get people completing it as England, 020 X XXX XXXX


Splitting a phone number field into multiple parts is navigating a course for future pain. Here are two reasons.

In some countries, there isn't one format, but many.

A New Zealand illustration. Early mobile phone subscribers got 6 digit subscriber numbers ...

  • 021 123 456
  • 025 123 456

This was at a time when land lines got 7 digit subscriber numbers

  • 03 123 4567
  • 09 123 4567

But now, mobile phone subscribers get 7 digit subscriber numbers - and to encourage old subscribers to move, some got to keep their 6 digit subscriber number

  • 021 123 4567
  • 027 123 4567
  • 0274 123 456

Phone number formats change

If there's one thing that's constant in the ICT industry, it's change.

In addition to the examples above, consider the changes experienced by my fathers retail business - each in turn, these were his business number format:

  • 03 44 1234
  • 03 484 1234
  • 03 348 41234

While these changes were all in the 1980's, this sort of change still happens - phone numbers in Australia changed from 7 to 8 digits in 1998.


"In general terms the international format for a telephone number actually is +<country> [(0)]<area> <subscriber>"

AS others have mentioned, there isn't really a "general" way phone numbers are formatted. For example here in Denmark all numbers are 8-digit but there is never a leading zero when calling in-country, so for a Dane that (0) would just be utterly confusing.

Also, up until the 1990s the first two digits indeed used to be <area> as mentioned, but now all danish telephone numbers are basically just random 8 digits – so the Danish format would just be +<country> <subscriber>

  • Hey Clint, welcome to UX! You answered on an old post that has already has an accepted answer. Usually we don't do that unless we can improve on the accepted answer. That said, I'm just a little confused when I read your answer. I get the feel it's more comment than answer. Could you maybe expand/explain the format you used in the beginning as it's the only thing that actually is an answer to the question? The rest seems to just be commentary on a specific example. That make sense? Mar 24, 2015 at 15:00

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