How to Format Phone Numbers in Email Signatures (and Keep Them the Same for Everyone)

Your sales director writes her number as (212) 555-0142. The office manager prefers 212.555.0187. The new hire in London pasted +44 (0)20 7946 0321 from an old business card.

Same company, three signatures, all sent before lunch.

Nobody did anything wrong. That is exactly why it never gets fixed.

Short answer: pick one format and stop relying on people to type it. National if the people you email are in your country, international with a plus sign if some are abroad. The staff list will never be tidy, so change how the signature shows the number. In BulkSignature that is one setting on the signature.

Even the rule books disagree

Each of those three could find a style guide that agrees with them.

The Associated Press says it dropped the brackets from its style in 2024 and now writes a number with hyphens. Microsoft's style guide also wants hyphens, "not parentheses, periods, spaces, or anything else." The international standard for writing phone numbers asks for a plus sign, the country code and spaces. The UK government's style guide shows an international number as +44 (0), with the zero in brackets.

None of these was written for email signatures, and between them they still cannot settle it. Your sales director's brackets were once Associated Press style. Your London hire writes her number the way her government does.

Where the mess comes from

Start with the staff list your company keeps in Google Workspace or Microsoft 365 (the directory). A phone number there is plain text, and for the most part nothing checks how it is typed. Google's own documentation says the number "may be in any telephone number format."

Several hands fill that list. IT types some numbers, an HR system sends others, and in Microsoft 365 people can change their own mobile number.

The built-in signature tools are no help with this. A Gmail signature is whatever each person typed. Microsoft's company-wide footer can pull the number from the staff list, and Microsoft's instructions offer no way to change how it looks. We compare the built-in tools for Google Workspace and for Microsoft 365 in separate guides.

What people see and what their phone dials

A phone number in a signature can be two things: the text people read, and a link behind it, which is what a phone dials when someone taps the number. The two do not have to match.

That takes some heat out of the argument about brackets and dots. When the link is right, the punctuation is only for the reader's eye.

When it is wrong, a number can look fine and still not connect. A number with no country code cannot be dialled as it stands from abroad. An extension glued onto the end can get dialled as part of the number.

So which format should you pick

The international standard has two forms. The national one is the number as it is dialled inside your country. The international one starts with a plus sign and the country code. For your sales director's number that means (212) 555-0142 or 212-555-0142 at home and +1 212 555 0142 abroad.

If everyone you email is in your country, use the national form. If some are abroad, use the international one.

Brackets, dots, hyphens or spaces inside the number are house style. The rule books will not settle it for you, so choose.

Then there is the zero in brackets, as in +44 (0)20. It is a British habit: the zero is dialled inside the UK and dropped from abroad, and the brackets are there to say so. Some UK style guides prescribe it. The international standard leaves brackets out of an international number, and software can misread them: in one reported case a calling app dialled the zero with everything else, and the call failed. British readers will not blink at it. For anyone else, +44 20 without the zero is the safer choice.

Whatever you pick, pick one.

Why fixing it by hand does not last

You can send everyone a memo with the approved format. We have a whole post on how well reminders work.

You can clean the staff list yourself, one number at a time. It stays clean until the next person joins.

Some signature tools let you write a pattern that rewrites every number. Fine, if somebody on your team wants to write patterns and keep them right for every country you have people in.

How BulkSignature solves it

In BulkSignature you design one signature for many people, and each person's details are filled in from the staff list. We left that list alone and changed what the signature shows. You choose how a phone number should look, once. Each person on that signature then gets their own number in that form, whether it was typed with brackets, dots, dashes or nothing at all.

There is no pattern to write. You pick your country and see one sample number written every way the list offers. For the United States that is (201) 555-0123, 201-555-0123, 201.555.0123, +1 201 555 0123 and so on. Choose the one that looks right. The list is in the General Settings of the Designer, our signature editor, in the section called Phone numbers.

It covers every phone and fax field in the signature, and you can add fields of your own that hold a phone number, a direct line for instance.

The link behind the number carries the full international number, country code included. So the signature can show (202) 555-0173, and someone abroad who taps it still dials the full number. Extensions are shown as "ext. 12" and kept out of the link, so a tap calls the main number.

Until you pick a format, every number shows exactly as it was entered. Publish the signature, and the new format goes out to everyone on it like any other change. There is nothing new to install.

Or just ask

The Designer has an assistant called Ask AI. Type what you want in plain words, for example "format the phone numbers like (202) 555-0173". It sets the format for the whole signature and tells you which one it chose. If that is not what you meant, one Undo takes it back.

Before and after

Six numbers the way six people typed them, with the country set to United States and the format set to (201) 555-0123.

Set the country to United Kingdom and pick the international form with spaces, and 020 7946 0958 shows as +44 20 7946 0958.

What it does not do

Back to the new hire in London. A signature has one country and one format. If yours is set to United States, her +44 (0)20 7946 0321 stays exactly as she pasted it: a number written with another country's code is left alone. The setting belongs to the signature, not the company, so a signature made for the London office can have its own country.

• A foreign number typed without its plus sign can be read as a local one.
• A field holding two numbers, or words as well as a number, stays as typed. Two numbers also get no link, because a link can dial only one.
• A number typed straight into the design, not pulled from a field, stays as typed.
• The list of forms is fixed. You cannot add a pattern of your own.
• It works in signatures built in the Designer, not in ones made with our older editor.
• Nothing reports which numbers were left as typed. Use "Preview as" to look at a few people's signatures before you publish.
• The staff list stays as untidy as it was. Only the signature changes.

FAQ

What is the best phone number format for an email signature?

There is no single correct one, and the style guides disagree. Use your country's national form if your readers are local, and the international form, with a plus sign and the country code, if some are abroad. Then use the same one in every signature.

Does BulkSignature change the numbers in Microsoft 365 or Google Workspace?

No. The format changes how a number is shown in the signature. The numbers stored in your staff list stay exactly as they are.

What happens to extensions?

With a format chosen, an extension typed as x12 or #12 shows as "ext. 12" after the number. It stays out of the link, so a tap calls the main number only.

Try it on your own signatures

Open your inbox and count how many ways your colleagues write a phone number, then pick one. BulkSignature has a 14-day free trial with no credit card required. Start the free trial.