Brand voice: how to actually give AI yours

The standard advice is to tell the model your tone of voice. So you open ChatGPT, type "write in a friendly, professional tone", and the output comes back friendly and professional and still reads like nobody wrote it. You try "warm but authoritative". Same page, different adjectives. You conclude the tool cannot do voice.

The short version: the instruction was never going to work, because friendly and professional is not your voice. It is every business's voice. Ask five competitors to describe how they talk to customers and you get the same handful of words back, which tells you exactly how much information those words carry. You have asked the model to narrow down to a description that does not narrow anything.

Worse, friendly and professional is already the default setting. That evenly warm, mildly helpful register is what these models produce when you tell them nothing at all, so the instruction is not just vague, it is redundant.

I have written separately about why AI content sounds generic and what it costs you in enquiries. This post is the other half: what to put in front of the model so the writing comes out sounding like you, built once rather than fought over every time.

Voice is not adjectives. It is specifics and opinions.

Here is the reframe that makes the rest of this easy. Voice is not how you sound. It is what you know and what you have decided about it, and the sound is downstream of that. Two people can write in identical registers and one of them is unmistakable, because they are saying things the other one cannot say. Broken into parts you can actually collect, it is four things.

The things you say that a competitor would not

Not a style, a fact. A landscaper who tells people flat out not to lay new turf in a Perth January, and what happens if they do. A physio who explains that most of the shoulders she sees are not shoulder problems at all. That is working knowledge, and nobody else in your suburb writes those sentences because they either do not know them or never thought to say them.

The positions you hold

Something you believe about your field that a reasonable competitor might argue with. Not manufactured controversy, and not a slogan. A real position you arrived at by doing the work, ideally one that costs you something to hold. A builder who thinks fixed-price contracts are worse for the client than cost-plus and will explain why. A clinic owner who does not think more appointments is the answer to a waiting list. This is the single biggest lever, and the one the model will never supply on its own.

If a sentence is something nobody could possibly disagree with, it is not voice. It is manners.

- Tom McSherry

The words you use for your own work

Every trade and every practice has its own vocabulary, and it is rarely the industry-average vocabulary the model reaches for. Do you say clients, patients, customers or people? Quote or estimate? Callout or visit? Sessions or appointments, and are they with a psychologist or with you by name?

There is also the negative list, which matters more than owners expect: the words you would never use about your own work. I have sat with clinic owners who visibly flinch at "solutions". If one of those words turns up in your copy, a regular customer knows straight away that you did not write it, even if they could not say which word gave it away.

What you refuse to do

The jobs you turn down. The shortcut you will not take even when the customer asks for it. The thing you talk people out of buying about once a week. Refusals are the sharpest voice signal available to you, because they cost something. Anyone can claim quality. Saying "I will not do a roof restoration on tiles that need replacing, and here is how to tell which yours are" says more about your standards than a page of adjectives, and no competitor can lift that sentence without also accepting the consequence of it.

How to capture it, cheaply

None of that sits in your head in an organised form, which is why people default to adjectives: adjectives are the only version that is easy to type. So do not type it. Two ways to get it out, both quicker than the prompt-fiddling you would otherwise do.

Option one: talk for fifteen minutes

Open the voice recorder on your phone, sit in the ute or the office with the door shut, and answer five questions out loud. Talking works better than writing because you stop performing. The version of you that explains something to a customer on site is the version you want on the page.

• Explain the last job you did to someone who knows nothing about your trade. Use the words you would actually use, including the ones for the parts.
• What do most people in your industry do that you think is wrong, and what do you do instead?
• What do you turn down, and why? Include the work you could take and choose not to.
• What do your customers call the thing you do, and what do you call it? Where do those two lists differ?
• What is the question you get asked most, and what is your real answer to it, not the polite one?

Then get it transcribed. Every phone and most note apps do this free now, and the raw transcript is fine. Do not tidy it up. The repetition, the sentence that changes direction halfway, the aside about the customer in Hamilton who ignored your advice twice, that is the material.

Option two: raid your sent folder

If fifteen minutes of talking to yourself sounds unbearable, you have already written the reference material. Open your email and copy ten or fifteen replies into one document. Not the one-liners: the ones where somebody asked a real question and you gave a real answer, probably longer than you meant to.

That is your voice under the least performance pressure it ever operates under. You were not writing marketing copy, you were trying to be understood by one person. Strip the names and anything confidential and it beats any brand guide you would sit down and write.

Feed it as examples, not instructions

This is where most people go wrong even after doing the work above. They summarise their voice into a description and hand over the description. "My tone is direct, a bit blunt, no jargon, short sentences." Still adjectives, just more of them.

Hand over the raw material instead. These models are far better at imitating something in front of them than at interpreting a description of something they cannot see. Paste three to five pieces of your own writing, the transcript, the emails, and say: here is how I write, match this. Then give the brief for the page separately, and be explicit about the split. Content from the brief. Style from the samples.

Two things sharpen it further. Give it a short do-not list from your negative vocabulary, because the model's defaults bleed back in over long drafts and you will find "bespoke" has crept into paragraph nine. And give it an anti-example: paste a paragraph of the generic version and say plainly, this is what I do not want. Showing the failure mode works better than describing it.

Build it once, use it forever

This is the part worth acting on even if you ignore everything else. It all collapses into one document, built once.

• Three to five samples of your actual writing or speaking, unedited.
• Ten to twenty specifics: the things you know that competitors do not say.
• Three to five positions you would defend, written as sentences somebody could argue with.
• Your vocabulary, in two columns. Words you use, words you never use.
• What you refuse to do, and the reason for each one.

That is your voice reference. It goes at the top of every content prompt from now on, for every service page, every location page, every email. It took fifteen minutes and it does not expire. Review it once a year, or when you add a service.

I keep coming back to this because of the maths. Almost everything else in SEO is a recurring cost: links have to keep being earned, rankings held against competitors, content maintained. The voice reference is a one-off fifteen minutes that improves every piece of writing you generate for years. I do not know of a better return anywhere in the process, and almost everyone skips it because it does not feel like work.

How to tell whether it worked

Do not ask whether the draft is good. It will be good. Clean grammar and sensible structure is the one thing you can rely on. The question is narrower: would a regular customer, somebody who has dealt with you a few times, recognise this as you? Four checks, in order of how quickly they settle it.

• Read it out loud. Any sentence you would not say to a customer standing in front of you is not yours. That test alone catches most of it.
• Ask somebody who knows how you talk. Your office manager, a long-standing customer, your partner. Ask "does this sound like me?", not "is this any good?". The second question gets you a compliment and no information.
• Look for something to disagree with. If nothing on the page could be argued with, no positions survived the draft.
• Search the page for the words on your never list. One "seamless" means the samples were too thin or the draft ran too long.

When a page fails these, the instinct is to rewrite the prompt. Usually the prompt is not the problem. Add to the reference document instead, because a thin reference produces thin voice however the prompt is worded. That fix compounds. Prompt tinkering does not.

What this does not fix

Voice is one gap of several. A page that sounds exactly like you can still be structurally wrong: targeting a keyword another page already owns, inventing a service you do not offer, linking to nothing sensible. Voice does not touch any of that, which is why planning comes first and writing second, the argument in plan before you generate and in the broader guide to using AI for your website content without wrecking it.

It also does not remove you from the process. Somebody who knows the business still reads the draft before it goes live, the same human in the loop I argue for everywhere else, and the day-to-day detail of where I draw that line is in how I actually use AI for SEO.

Where to start

Do not buy a tone-of-voice template. Pick up your phone, answer the five questions out loud, and get the recording transcribed. If that is too much this week, copy fifteen good replies out of your sent folder instead. Either way you end up with something in under half an hour that no competitor can replicate, because it is made of things only you know and things only you have decided.

The adjectives were never really the problem. The problem is that you were describing your voice to something that had never heard it. Stop describing it and show it, once, properly, and every page after that gets easier.