UK English vs. US English Punctuation: Key Differences

If you’re working as a freelance proofreader, you’ll likely encounter documents written in both UK and US English. And while these dialects share many similarities, there are some crucial differences that can affect your work.

Most people know about spelling and vocabulary differences (like organise vs. organize or trousers vs. pants). But when it comes to punctuation, there are several lesser-known distinctions that are just as important.

In this post, we’ll look at the key punctuation differences between UK and US English that every proofreader should know:

1. Date formatting
2. Punctuation of titles (such as Ms. and Dr.)
3. Quotation mark conventions
4. Capitalization after colons
5. Latin abbreviations (such as e.g., i.e., and vs.)
6. Acronyms and initialisms

Let’s take a closer look.

1. Dates 

One of the most common issues when proofreading across dialects is date formatting. UK and US English use different structures as standard:

• UK English: Day–Month–Year (5 August 2025 or 05/08/25)
• US English: Month–Day–Year (August 5, 2025 or 08/05/25) 

In US English, a comma is used before the year when writing the date in full. The year is set in a pair of commas when it appears in the middle of a sentence. This is to separate the number for the date from the number for the year:

The meeting is on August 5, 2025, at 3 p.m.

In UK English, no comma is needed between the elements:

The meeting is on 5 August 2025 at 3 p.m.

Always check that the date format matches the dialect, and be especially careful with numeric-only dates, which can be easily misread between systems. For example, 05/08/25 means 5 August in UK English but May 8 in US English.

2. Titles and Abbreviations

Titles before people’s names are punctuated differently in UK English vs. US English. 

In UK English, a period is only used if the abbreviation omits the final letter of the full word. This means Mr (from Mister) and Dr (from Doctor) do not take a period, while Prof. (from Professor) does, since it drops the end of the word:

Mr Holmes

Dr Watson 

Prof. Moriarty

In US English, all such titles take a period, regardless of how the word is shortened:

Mr. Holmes

Dr. Watson

Prof. Moriarty

When proofreading, keep an eye out for inconsistent title punctuation – especially in documents that may have been edited by multiple people or use a mix of UK and US sources.

3. Dialogue and Quotations

In UK English, single quotation marks are standard for primary quotes. Double quotation marks are used for quotes within quotes: 

‘Time to get ready!’ she shouted.

‘He stood up,’ Jo explained, ‘and then he said, “I’m leaving.”’

In US English, double quotation marks are used for primary quotes. Single quotation marks are used to set apart quotes within quotes:

“Time to get ready!” she shouted.

“He stood up,” Jo explained, “and then he said, ‘I’m leaving.’”

This is the case for both dialogue and quoted extracts from a written source. But that’s not all to remember about punctuating quotes!

When quoted material is presented in UK English, the following punctuation only goes inside the closing quotation mark if it’s part of the original text:

Wilkinson states, ‘Punctuation marks can be confusing’.

Sanderson claims that ‘punctuation is as easy as pie’, but many find it harder than understanding pi.

However, in US English, commas and periods that come after the quote always go inside the closing quotation mark, even if they’re not part of the original material:

Wilkinson states, “Punctuation marks can be confusing.”

Sanderson claims that “punctuation is as easy as pie,” but many find it harder than understanding pi.

Be especially vigilant when proofreading quoted material. Misplaced punctuation or mismatched quotation styles can undermine clarity and make academic or professional writing look careless.

4. Colons 

The rule for capitalizing the word following a colon is different in UK and US English.

In US English, a capital letter is used after a colon if the phrase is an independent clause (i.e., a full sentence or complete idea):

Her message was clear: Get out safely.

In UK English, the word following a colon typically begins with a lowercase letter, even when it introduces a full sentence. A capital letter is only used if the word would be capitalized anyway (e.g., a proper noun):

Her message was clear: get out safely.

He offered one solution: Canada.

Regardless of dialect, colons are used to introduce explanations, expansions, and lists. Be sure to check that usage is both logical and grammatically correct.

5. Latin Terms

Latin abbreviations such as e.g., i.e., and vs. are punctuated slightly differently between US English and UK English.

In US English, it’s standard to follow e.g. and i.e. with a comma:

I love citrus fruits, e.g., oranges and lemons.

In UK English, this comma is not standard and is typically omitted:

I love citrus fruits, e.g. oranges and lemons.

You’ll also see differences in how versus is abbreviated. This word can be shortened in two different ways – as vs or simply as v, especially in legal contexts – and the punctuation depends on the dialect. 

In UK English, it’s far more common to omit the period after vs or v:

Carlisle United vs Millwall was the best match of the season.

Donoghue v Stevenson set a vital precedent in English law.

In US English, still use vs. or v. depending on the context, but it’s usual to add a period at the end:

Portland Timbers vs. Seattle Sounders is a real match of rivals.

Marbury v. Madison paved the way for judicial review.

As you proofread, check that these terms are used and punctuated consistently, and avoid mixing dialect conventions within the same document.

6. Acronyms and Initialisms

Acronyms and initialisms are presented differently depending on the specific term but also on the dialect.

In US English, it’s more common to add periods between the letters in initialisms:

U.S.A.

F.B.I.

P.T.A.

In UK English, the periods are usually omitted:

USA

FBI

PTA

When proofreading, make sure periods are used or not according to the client’s preferred dialect. And if in doubt, focus on consistency in the text.

Master UK vs. US Punctuation with Knowadays

Want to sharpen your proofreading skills and get to grips with the differences between UK and US English?

Our Becoming A Proofreader course includes an entire module dedicated to punctuation, as well as modules on spelling, grammar, and other common errors. And throughout, it explains the differences between US and UK English so you can proofread confidently in either dialect.

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