• 3-minute read
• 24th August 2026

Should a Comma Go Before or After “But”?

The dos and don’ts of commas can be confusing, especially when it comes to conjunctions such as “but.” Whether a comma should go before or after “but” depends on the specific sentence and the context in which it’s used. Getting this right matters in writing where even small punctuation errors can undermine credibility. When reading a report, for example, a reader might misinterpret a grammatical error as sloppiness or inattention to detail, which might reduce their trust in the rest of the content. In this post, we’ll explain when to use a comma with “but” and demonstrate with clear examples.

Use a Comma Before “But” To Join Independent Clauses

Writers most commonly use the word “but” as a conjunction that introduces a contrast or exception to what has been previously stated. It often signals a contradiction or shift in thought. Use a comma before “but” when it connects two independent clauses (parts of a sentence that could stand alone as complete sentences). For example:

Note that you should only use a comma when connecting two independent clauses. Don’t use a comma before “but” if what follows could not stand alone as a complete sentence. For example:

In the first pair, the second sentence needs a comma before “but” because what follows is a complete thought with a subject and predicate. In the second pair, the phrase “but left early” is not an independent clause, so it doesn’t need a comma.

This distinction is especially important in professional writing. A misplaced comma in a proposal or client email can create ambiguity. Readers may pause or reread a sentence, which disrupts the flow of your message.

Use a Comma After “But” To Set Off Parenthetical Phrases

If you use “but” within a sentence to set off a parenthetical clause (a phrase that adds extra information but isn’t essential to the sentence’s meaning) or an interrupter, you should use a comma after “but.” If what follows is an independent clause, then you use a comma before and after “but.” For example:

Note that it’s not strictly necessary to use commas to set off short phrases like “of course,” “in fact,” or “unfortunately” if they are an essential part of the sentence. When deciding whether to use commas in these situations, consider the clarity of your writing. Ask yourself whether commas would enhance or disrupt the overall flow of the sentence. In formal reports or client-facing content, erring on the side of clarity is usually the better choice.

Apply the Rule Consistently Across Your Content

Consistency is key in any professional document. If you choose to set off interrupters with commas after “but” in one paragraph, apply the same approach throughout. Inconsistent punctuation can make your writing feel uneven and reduce reader trust.

Here’s a quick reference:

• Use a comma before “but” when it joins two independent clauses
• Skip the comma before “but” when what follows is not a complete sentence
• Use a comma after “but” when a parenthetical phrase or interrupter immediately follows it

Keeping these rules in mind will help you produce stronger proposals and more precise reports.

Get Expert Proofreading for Your Content

Even experienced writers second-guess comma placement. Our expert proofreaders catch punctuation errors, inconsistencies, and unclear phrasing so your content reads exactly as intended. Upload your document to  Proofed for Business today to see the difference professional proofreading makes.