This week I received a proof for a booklet I am printing. Because the print run is 2000 copies, I wanted to be sure everything was perfect. That is why I double-checked how to render our business phone number in print. Coincidentally, Jennifer from Bozeman, Montana, wrote to me the same day, asking for guidance on "telephone number etiquette." Jennifer noted that she has seen graphic designers use periods (dots) between the parts of a telephone number instead of parentheses and hyphens.
Which style or format is correct? As usual, style guides differ. Of the ones on my bookshelf, The Gregg Reference Manual takes the most liberal approach. Gregg offers many possibilities, which I illustrate here with my office number:
206-782-8410 This format is most common, according to Gregg.
(206) 782-8410 This style is common, says Gregg, but can't be used when the telephone number itself appears in parentheses. Also, this format makes less sense in large metropolitan areas in which the area code is required even for local numbers.
All these are acceptable on letterhead and business cards, according to Gregg:
206/782-8410
206.782.8410
206 782 8410
To connect the parts of international phone numbers, Gregg uses hyphens.
Another style guide, Microsoft Manual of Style for Technical Publications, recommends parentheses around the area code, with the parts of the local number separated by a hyphen, like this:
(425) 555-0122
Microsoft labels the all-hyphen style as incorrect and does not even mention periods or dots.
For international numbers with country and city codes, Microsoft uses one set of parentheses around the country code followed by a second set enclosing the city code, like these codes for London, England: (44) (71). These numbers in parentheses are followed by the local number rendered in the style used by the particular country.
The Associated Press Stylebook (AP) agrees with the Microsoft Manual--mostly. Like Microsoft, it rules that parentheses be used around the area code, with hyphens between the parts of a local number. However, AP uses one set of parentheses around both the country and city code, like this: (44-71) followed by the local number. AP advises against periods.
The Chicago Manual of Style offers no rules. It states only that parentheses are sometimes used around the area code but hyphens are more common.
The Canadian Press Stylebook uses hyphens.
How should telephone numbers be formatted? Based on my review of these reference books, I would say hyphens are the best bet.
But there is something much more important than format.
Before printing a few thousand copies of a booklet or business card, before placing that costly ad in the newspaper, be sure the phone number itself is correct. Check it several times. Then have someone else proofread it. When readers want to phone you, the number itself is far more important than any style choice.
Lynn


Useful info - but a bad example for London. The area code for London is not (44) (71), and hasn't been for many years now. It's now (44) (20).
Years ago, the dialling code for London within the UK was simply 01. Then it changed to 071 (inner London) and 081 (outer London). A few years ago, this changed to 020 for the whole of London, with 020 7... being inner London, and 020 8... being outer London.
Posted by: Chris Mitchell | October 23, 2007 at 02:56 PM
Chris, thanks for this correction. I used an example from the "Microsoft Manual of Style for Technical Publications," published in 2004. I hope someone at Microsoft Press will read your comment.
Lynn
Posted by: Lynn | October 28, 2007 at 02:03 PM
We use parens to distinguish the "optional" part of the phone number. It's a simple premise and easily applies to international numbers.
If you're dialing from within the (area code), for example, it indicates the part of the number you do not need to dial.
When publishing a toll-free number, we don't use parens as the full number is required for all users.
example:
(1) (415) 123-1234
(415) 123-1234
1-800-123-1234
Posted by: Jen | December 03, 2007 at 01:16 PM
Jen, your approach makes sense. Thanks for sharing it.
Lynn
Posted by: Lynn | December 03, 2007 at 07:12 PM
I find it amusing that Microsoft is publishing technical manuals when more often than not I am having to ignore its interpretations of correct spelling and/or grammar!
Posted by: Jackie | April 03, 2008 at 12:17 PM
Hi, Jackie. Brilliant humans write the style manual. Although brilliant humans also design the software, ultimately it's just a software program guessing where your introductory clause ends. That's why we have to use our grammar and spelling checkers as a guide--not as gospel.
Thanks for commenting.
Lynn
Posted by: Lynn | April 03, 2008 at 02:54 PM
I don't understand how Microsoft can accept the parentheses when in many areas the entire phone number is required. In my thinking, which can be flawed also, I can't think of a time when parentheses would be appropriate unless what was in the parentheses did not need to be dialed. I'd like to see Microsoft move ahead in this area. I received 4 documents from large organizations today, all using dots between the number. I also see hyphens but almost never see parentheses. When I do, my mind goes to "old-school". As a side note, dots & hypens are much easier to type because you can use your number keypad for the entire number.
Posted by: Dee Combs | August 29, 2008 at 10:02 AM
As someone whose number keypad just gathers dust, I was glad to be reminded that some people use it. Thanks for commenting, Dee.
Posted by: Lynn | August 30, 2008 at 03:28 AM
From my North America perspective, is there any guideline on using the plus "+" character as the first character in international phone number? I am considering standardizing this in my own database system to represent any number other than one following the North American Numbering Plan (NANP). I was thinking this would be a nice visual cue to more easily distinguish these different types of numbers; the database I inherited has maybe 25% of the int'l numbers in it formatted like this, and I'd like to get them all following the same format. Thanks!
Posted by: Funka! | October 28, 2009 at 12:00 PM
How do you write a an address in AP style for a London address?
Example:
the EcoBuild tradeshow at the ExCel London in London, United Kingdom from March 1 - March 3.
Posted by: Andy Penney | February 16, 2011 at 02:26 PM
Andy, in AP style the months are abbreviated, so you probably want to use Mar. 1-3. I believe your sentence should use London, England, with a comma after the country name.
If the tradeshow is billed as EcoBuild Tradeshow, capitalize the word "Tradeshow."
Lynn
Posted by: Lynn Gaertner-Johnston | February 17, 2011 at 06:19 PM
Hi Lynn,
Any thoughts on whether you should use hard or soft hyphens in phone numbers? There is great debate in our office with some individuals insisting on hard hyphens in phone numbers.
Posted by: Murry | February 23, 2011 at 10:48 AM
Murry, thanks for the question. I believe hard hyphens are an excellent choice in telephone numbers.
Here is a loose definition of a hard hyphen: A hard hyphen is one that will not break the word or item at the end of a line. In Microsoft Office, it is called a "nonbreaking hyphen" and can be found under Special Characters.
The reason to use hard hyphens in phone numbers is to ensure that a number will not be broken at the end of a line.
In my writing I don't normally use hard hyphens in phone numbers, but I do check for breaks in numbers at the end of lines. Then I insert a hard hyphen if needed. For people who may not see the final copy (as I always do), using hard hyphens is a good habit.
Lynn
Posted by: Lynn Gaertner-Johnston | February 28, 2011 at 09:22 AM
What is the correct way to write phone numbers with extension on resumes? Thank you
Posted by: Diane Lynch | March 01, 2011 at 06:47 PM
Diane, there are probably many correct ways to include an extenstion. I like this approach:
555-555-5555, Ext. 505
Good luck with your resume.
Lynn
Posted by: Lynn Gaertner-Johnston | March 01, 2011 at 10:12 PM
Chris Mitchell is right, except that 020 is the code for the whole of London, and the first digit of the number (e.g. 7) is irrelevant.
To display numbers in international format, the correct format worldwide is as follows: e.g. +1 212 736 5000 or +44 20 7222 1234. A plus sign before the country code... NO brackets, just spaces.
Posted by: Duncan Hill | December 13, 2011 at 06:47 AM
Hi, Duncan. Thank you for your good advice. Some style manuals also use hyphens between the various parts of the number.
Lynn
Posted by: Lynn Gaertner-Johnston | December 13, 2011 at 10:31 PM