How to define your brand voice

24 August 2026 · Nunya Bunya

The five-minute decision you keep making from scratch

You sit down to write a caption, an email reply, a website update, whatever it is, and before you've written a single word about the actual thing you're doing, you've made three decisions: how formal to sound, whether a joke fits, and how much detail is too much. Then you finish, read it back, and change your mind about all three. Multiply that by every post, every email, every product description, and you can see where the hours go. It's not that the writing is hard. It's that you're solving the same problem over and over, from zero, every single time.

A brand voice guide exists to stop that. Done properly, it's just a written record of the decisions you've already made, so you stop remaking them.

What a brand voice actually is

Brand voice is simply how your business sounds when it talks, as opposed to what it says. Two businesses can sell the exact same service and sound completely different: one calm and matter-of-fact, one warm and chatty, one dry and a bit cheeky. Neither is wrong. The problem isn't picking the wrong voice. It's not picking one at all, so every piece of writing reflects whatever mood you were in that day.

The method, step by step

Here's a way to actually do this, not just think about it. We'll use a mobile mechanic as the example, a made-up one, not a real client, just to make it concrete.

Step 1: Pick three or four words for how you sound, not what you sell

Not "reliable" or "professional". Every business on earth claims those, which means they describe nothing. You want words specific enough that you could point at a sentence and say "that's it" or "that's not it".

Our mechanic picks: direct, unbothered, a bit dry. Notice these are about tone, not values. "Trustworthy" is a value. "Direct" is a way of talking.

Step 2: Write the opposite of each word

This is the step almost everyone skips, and it's the one that actually makes the guide useful. A word on its own is a vibe. A word with its opposite next to it is a boundary you can check writing against.

Now if a draft comes out sounding chatty, you don't need to have an opinion about it. It fails the second one. Done.

Step 3: Set three concrete rules you can actually check

Turn the words into things you can look at on the page: sentence length, formality, and how you handle bad news or mistakes. For the mechanic:

Step 4: Test it on something real, twice

Take one actual message you'd send, a booking confirmation, say, and write it two ways: once in the voice, once in whatever your default is. Put them side by side.

Default: "Hi Sarah, just wanted to let you know we've had a look at the car and unfortunately it looks like the issue might be a bit more involved than we initially thought, so we'll need a little more time to sort it."

In voice: "Sarah, it's not the belt, it's the tensioner. That's another hour and about $80 in parts. Car will be ready by 3."

Same information. One of them sounds like an actual person who knows what they're doing. The test isn't which one you like better in the abstract, it's which one matches the three words from step one. That's what makes the guide a decision-making tool instead of a mood board.

Step 5: Write it down as a one-page reference

Words, opposites, the three rules, and the two example sentences side by side. One page. If it's longer than that, nobody will open it before writing an email, which defeats the whole point.

What good looks like, versus what most people produce

Most brand voice documents that get written are a list of adjectives with no teeth: "friendly, professional, approachable, trustworthy." You could staple that page to any business in the country and it would fit. It gives you nothing to check a sentence against, so it sits in a folder and everyone keeps writing on vibes.

A good one is specific enough to be almost uncomfortable. It tells you what you sound like and, just as importantly, what you refuse to sound like. It includes actual sentences, not just words describing sentences. And it's short enough that you could genuinely hold it in your head after reading it twice.

Three mistakes that make the whole exercise pointless

The first is picking words that could describe any business. If "professional" and "friendly" are your two big ones, you haven't defined anything yet, you've just described the minimum bar for being in business at all.

The second is skipping the opposites. Without a boundary, every word is just a compliment you're paying yourself. "Direct" without "not vague" doesn't stop anyone writing a padded, apologetic email, because nothing in the document contradicts it.

The third is never testing it against real writing. It's easy to agree on three words in the abstract and much harder to notice, in the middle of writing an actual email, that you've drifted back to your old habits. If you never run a real sentence through it, the guide stays a nice idea instead of a tool.

What to do with it once it's written

This is the part most guides on this topic skip entirely: writing the document isn't the finish line, using it is. Put it somewhere you'll actually see it, next to wherever you write, not buried in a drive folder you open twice a year. Before you send anything longer than a couple of lines, run it past the three rules for ten seconds. If you ever bring on someone else to write for you, hand them the page before they write a word, it'll save you a dozen rounds of "can you make this sound more like us". And check back on it every six months or so, because how you sound now might not match how the business has grown.

Doing this properly takes an afternoon, and if you'd rather have it done for you, a Brand Voice & Tone Guide built from your own answers is $99.