October 06, 2006
Internationalization and phone numbers
We are redesigning our registration form. We've had a debate as to the best method of presenting a phone number field in a form for international users. We can leave one long field, or we can set the phone field appropriately depending on the country (for example, 3 separate fields for U.S. and Canada: one field for area code, another field for the first set of 3 digits, and another field for the second set of 4 digits). What are your thoughts on this?
Both solutions are appropriate, but certain types of users and certain types of usage make one answer more likely to be correct than the other. If the users are trained “expert users,” such as call center reps who enter international phone numbers all day long, then a single long field for numeric values may be more appropriate. A single field may be quicker, depending on technology that might require the users to wait for the form to refresh after a value such as “Country” is entered in the form.
For consumer users of a single-use application, if the phone number is a critical field (for instance, if the form data will be used to ship items and an invalid phone number will delay or prevent shipping), then validation becomes more critical. Here, breaking out the correct format into multiple fields (perhaps even with examples) may be your best solution.
Auto-tab is also a consideration when the fields are broken out. Generally, we think this is not good for single-use applications, as we’ve seen users get confused when they make a mistake (“How do I go back to the field before this one?”), but test this with your users to make sure.
Lastly, Jakob Nielsen has a good Alertbox column about the minimal requirements for international sites.
Good luck—let us know what you choose and how it works for your users.
