How to create a tone of voice that works for people and AI

How do you create a tone of voice?

You create a tone of voice in five steps: find the voice you already have, turn it into three to five traits, set how the tone shifts by situation, write it down as rules with examples, then test it. Before you start, you need a brand platform that says what you stand for. A voice without a position just sounds pleasant.

At IW Agency, we think a tone of voice now has two readers. One is the copywriter, the support agent, the CEO drafting a post. The other is the language model they increasingly ask to write for them.

The difference shows in a single line. "We're warm and approachable" gives a model nothing to work with. "Speak as we to you, no exclamation marks, one idea per paragraph" does. If you don't have the foundation yet, start with what a brand platform is and when you need one.

Conclusion: If a machine can't follow it, people won't either.

How do you find the voice your brand already has?

You find it by collecting what the brand already says. Then you separate the lines that sound like you from the ones that could belong to anyone. Most organisations already have a voice. It is just scattered across a hundred authors.

1. Gather the material. Packaging, website, support replies, job ads, the CEO's last speech. Include the channels nobody polishes.

2. Mark the best and the worst. Which lines would a loyal customer recognise without the logo? Which could a competitor publish unchanged?

3. Hold it against the platform. The voice should carry what the brand believes. A brand that promises clarity can't hide behind 40-word sentences in its FAQ.

4. Read your audience. Their situation decides what the voice has to do.

We would rather find a voice than invent one. A voice dreamt up in a workshop rarely survives its first complaint email. In the SOS Barnbyar case, donors were demanding greater clarity and transparency as competition for attention increased. A voice for that situation starts with plain language, not adjectives.

How do you turn the voice into traits people can use?

You turn the voice into three to five traits. Each trait gets a one-word name, a scale position, a boundary and an example line. Fewer traits stick, and more start to contradict each other.

1. Name it and say why. Mailchimp's guide opens with "We are plainspoken". It then explains that its customers live in a world "muddled by hyperbolic language, upsells, and over-promises" (Mailchimp Content Style Guide).

2. Place it on a scale. Nielsen Norman Group describes tone along four dimensions: funny vs serious, formal vs casual, respectful vs irreverent, enthusiastic vs matter-of-fact (Nielsen Norman Group, 2016). Marking your position on each turns "friendly" into something you can check.

3. Write the boundary. Without a limit, warm drifts into gushing.

4. Show one real sentence. It teaches more than a paragraph of description.

We think the don't matters more than the do. Scales also show how far apart two brands can be. A chocolate milk whose name means "stupid" in Swedish, like Pucko, has room for irreverence that a global water company like Grundfos rarely needs. The scales are the same, but the positions are not.

How do you adapt the tone to different situations?

You keep the voice fixed and let the tone move with the situation and the reader's state of mind. Mailchimp puts it simply: "You have the same voice all the time, but your tone changes" (Mailchimp Content Style Guide).

1. List your moments. A thank-you, a complaint, a price rise, a launch, a legal notice.

2. Set the volume for each moment. Mailchimp suggests informal and lighthearted for a thank-you after a purchase, but serious and empathetic for a complaint (Mailchimp).

3. Write one example per moment.

We think a simple dial beats a long matrix. It has three settings: loud for campaign lines, mid for articles, quiet for definitions, FAQs and facts.

Take a late order. "Oops, our bad" and "Sorry, your order is late. Here's what we're doing about it" are both friendly. Only the second reads the room.

How do you write tone of voice guidelines an AI can follow?

You write them as explicit instructions: rules, banned words, sentence lengths and before-and-after examples. Mood words are not enough. A language model can't ask what "confident but humble" means, and its guess tends towards the generic.

1. Translate adjectives into rules. "Distilled" becomes "average 12–15 words per sentence, none over 30".

2. Keep a list of standards. Mailchimp recommends spelling out what to do and what not to do, including words to avoid (Mailchimp). For AI, the don't-list carries extra weight. It should name the clichés a model reaches for first.

3. Pair the examples. Put the off-brand draft next to the on-brand rewrite. For people and models alike, examples carry tone better than descriptions.

4. Separate rules from judgement. Spelling, product names and banned words are rules. Rhythm and wit are judgement, so show them.

We think one guide is the point. A version for people and another for prompts will drift apart. Consistent language across your own channels also gives assistants a clearer picture of you. That matters for how your brand shows up in ChatGPT.

How do you know your tone of voice is working?

Your tone of voice works when people recognise the brand without its logo and different writers sound like one company. AI drafts are another sign: they need edits, not rewrites. It also deserves testing like any other part of the experience.

Nielsen Norman Group compared pairs of nearly identical web pages in which only the tone varied. Tone measurably changed how friendly, trustworthy and desirable users found the brand. Trust, in turn, strongly predicted willingness to recommend (Nielsen Norman Group, 2016).

1. The blind test. Strip the logo from five pieces of content. Can customers tell which are yours?

2. The many-authors test. Put a job ad, a support reply and a campaign line side by side. Do they sound related?

3. The machine test. Give the guide to an AI tool and ask it for a product description. Count the edits.

We would judge a guide by that edit count above all.

Conclusion: A tone of voice is finished when someone else can use it.

What does this mean for your brand?

• Start with the platform. Decide what you stand for before deciding how it sounds.

• Cap the traits at five. Give each one a do, a don't and an example line.

• Write for the machine reader. If a rule can't be checked, rewrite it until it can.

• Keep one guide. People and AI tools should work from the same document.

• Test, then revise. Rerun the blind test after every major launch.

Frequently asked questions

What is the difference between brand voice and tone?

Voice is the brand's constant personality. Tone is how that voice adjusts to the situation and to the reader's mood. Mailchimp compares it to talking differently to close friends and to your boss while staying the same person.

How long should tone of voice guidelines be?

Tone of voice guidelines should be short enough that people actually read them. Traits, a volume dial, a word list and paired examples can fit on a few pages.

Can AI write in our brand voice?

AI can write in your brand voice if the guidelines are explicit. Rules, banned words and paired examples give a model something to follow. Adjectives alone do not.

Where can I find brand voice examples?

Mailchimp's Content Style Guide is public. Mailchimp also points to published guides from IKEA, Virgin Mobile Australia and Emory University.

A voice anyone can carry

A tone of voice is a set of decisions about how a brand sounds, written down so that anyone, or anything, can carry them. Get those decisions right and the brand sounds like itself wherever it speaks. If you want to talk about yours, write to us at hello@iwagency.com.

Sources

• The Impact of Tone of Voice on Users' Brand Perception — Nielsen Norman Group, 2016

• Content Style Guide: Voice and Tone — Mailchimp

• 7 Steps for Establishing Your Voice and Tone Guidelines — Mailchimp