How to Format 10-Digit Phone Numbers

The Associated Press Stylebook, on Threads:

We updated our style for telephone numbers in 2024 to drop parentheses. We now recommend the form: 212-621-1500.

For international numbers use 011 (from the United States), the country code, the city code and the telephone number: 011-44-20-7535-1515.

Use hyphens, not periods. No parentheses. The form for toll-free numbers: 800-111-1000. If extension numbers are needed, use a comma to separate the main number from the extension: 212-621-1500, Ext. 2.

I have long been annoyed that U.S. phone numbers are so often formatted in the outdated (123) 555-1234 format. The use of parentheses for the area code dates back to the old days, when you only needed to dial the area code to call a number outside your own area code. (The same era whence comes the verb dial.) Until 10-digit dialing with mandatory area codes started to become standard in the late 1990s, you only needed to dial seven digits to call a local number.

Apple’s Contacts app (and I think the system-wide Contacts framework, used by third-party apps like Flexibits’s excellent Cardhop), will go so far as to reformat numbers entered in 123-555-1234 format as (123) 555-1234. Apple should update the formatting to go the other way, and turn phone numbers with the area code in parentheses into the 123-555-1234 format. It’s only because area codes used to be optional that they were put in parentheses. Given that 7-digit dialing is never going to return, we should abolish the parentheses too.

★ Thursday, 16 April 2026