International Phone and Address Data?

Question

I guess this is a multi-part question. I am building a membership site and want to have the accounts as international as possible.

1. What is the best way to collect phone numbers on a form that allows for international numbers? I'm not worried about storing them, just collection and validation. What I have now is a drop down with a country list that will add the country code, and then the number itself with validation for us/can/uk based on the country code, and then the extension. These will be stored as strings in 3 fields for cc/number/ext Does anyone have a better, solid solution for this, or perhaps seen one in action anywhere?

2. Ditto for addresses. What is the best way to go? Address/City/State/Zip/Country or just lines? I would like to be able to sort by these, so a single text field isn't a very good solution, though it is the most flexible.

   This is also important because we may be sending actual mail to our members. I am put in mind of a few members I've had for other services that had addresses in countries I had never heard of, that even the woman at the post office couldn't tell if they were formatted correctly.

3. I want to have geodata in the db, at least country/state, for things like populating a state dropdown after selecting a country, field standardization, etc. Does anyone know of a great database that can be used as the geodata base of an app?

Answer 1

Phone number validation - I'm not sure if I'd spend a lot of time on this. Numbering schemes change quite often (for example, during the time I lived in the UK, the phone numbers for London area codes changed at least once, with another change shortly before I moved there) and in Germany it is (or at least used to be) quite common to increase the number of available phone numbers on a given exchange by taking an old number and tacking an extra digit or two at the end. So any assumption about a given phone number format will change and you'll end up playing catch-up. If you insist on splitting the phone number into international/area code/main number you'll probably find that this is a very country-specific way of representing the information so you'll need an input mask pretty much for every country and specific validation rules. Not to mention that in places like Germany, an area code can have between two and four digits etc...

Regarding postal addresses, the most important suggestion I have is to ensure that you can accept non-numeric post/zip codes, otherwise you won't be able to handle addresses in Canada and the UK (and possibly other places). This is a bit of a hobby horse of mine as I've had a few issues with websites in other countries that simply refused to let me put in a non-numeric post code and I had to resort to faxing over my address information as I couldn't fill in the online application form. In my book that's bad karma if you allow international customers....

Also, assuming the existence of certain parts of the address (state/county, for example) and requiring them is usually more of a headache than it's worth. I'd be tempted to offer the standard house number + street (combine them, different languages put the house number in different places so separating them out is not a good idea IMHO unless you know how to reassemble them correctly, plus sometimes you'll end up with a house name instead of a number), town and zip/post code, possibly with an optional county/state field. If you want to be really helpful to you international audience, offer a free-form, single text entry field for those addresses that don't conform to our "standard" assumptions of how an address looks. And please make them big enough so people with quite long addresses don't run out of space...

Answer 2

There is an international standard for telephone numbers, but it leaves a lot of breathing room. Separators are not mandatory, but are restricted to space, period, and hyphen. Round brackets (aka parentheses) are to be put around digits which are optional depending on where you are dialling from. For example, the area code is optional in some areas. I would provide a text field and let the user enter their number however they want.

For addresses, provide lots of fields and don't restrict too much. House numbers sometimes contain letters. Road types are sometimes written in full, and other times abbreviated. (St = Street, Ave = Avenue, etc.) I would provide drop-downs where possible (state/province), but allow freeform input when you don't have a list. When the user is entering their address, it's ok to validate for security risks, but you might want to leave geographical validation until later. For example, if the user enters a postal code of T8N 4E3 and selects Ontario as their province, the address is not valid because the given postal code is for Alberta. Display a friendly message to the user letting them know that they need to correct their address or contact you if it's correct (possible bug in your code).