Almost every brand voice document says the same three words: authentic, friendly, professional. Those documents change nothing, because they contain no decisions. A voice guide is useful in proportion to how many arguments it settles, and settling arguments requires rules a person can be wrong about: banned words, a stance on contractions, a rule for what happens when you have to apologise.
Voice and tone are different objects
Voice is the constant; tone is the variable. Mailchimp’s public content style guide puts it plainly: you have the same voice all the time, but tone changes, the way you speak differently at dinner with friends than in a meeting with your boss. The reason this distinction earns its place in a guide is that most voice failures are actually tone failures, a jokey line landing in a billing dispute or an outage notice, and a document that only describes voice gives the writer nothing to reach for.
Define the voice with limits, then with words
Three traits, each with an explicit boundary. Friendly but not chummy. Expert but not condescending. Direct but not blunt. The boundary is the operative half: without it, "friendly" drifts toward exclamation marks over eighteen months of content, and nobody can point to the moment it went wrong.
Then add the layer most guides omit, which is a word list. Ten words you use and ten you do not, with the substitutions named. Mailchimp’s guide takes a similar line on plain English, avoiding slang and jargon and favouring active voice. Word lists are enforceable in a way adjectives are not, and they are the only part of a voice guide that survives being handed to someone who has never met you.
| Vague version | Usable version |
|---|---|
| “Be conversational” | Use contractions. Second person. No sentence over 25 words in body copy. |
| “Be professional” | No exclamation marks outside onboarding. Never use “sorry for any inconvenience”, say what went wrong and what you are doing. |
| “Be clear” | No unexplained acronym on first use. If a sentence needs a comma to survive, split it. |
| “Be expert” | Lead with the number or the decision rule. If you cannot cite it, cut it. |
| “Be friendly” | Greet by name, sign with a person’s name, never “the team”. |
The messaging framework: four blocks, with proof attached
- Value proposition: one plain sentence naming the outcome, not the mechanism. Test it by asking whether a competitor could paste it onto their homepage unchanged.
- Three key messages: the points you want remembered after any single interaction. Three, because five means none.
- Proof points: a named number, a named client, a certification, or a case with a date. Anything unprovable belongs in the bin, not in the brief.
- Objection handling: the three reasons people do not buy, and your written answer to each. Sales already knows these. Marketing usually does not ask.
The objection block is the one worth arguing for. Most messaging frameworks are written from what the business wants to say, which is why they read as brochures. Written from the top three objections, the same framework reads as a conversation, and it gives every writer a set of specific problems to solve rather than a mood to evoke.
Voice guides now have a second audience
Anything drafted by an AI tool defaults to a generic register: heavy on abstractions, hedged, structurally symmetrical, adjective-rich. That default is more or less the exact opposite of a distinctive brand voice, which means an unenforced voice guide now produces drift faster than it used to. The countermeasure is the same set of concrete artifacts: the banned word list, the boundary limits, and a handful of before-and-after examples. Those work as prompt material as well as editorial standards, which is a genuine argument for writing them down properly.
Key takeaways
- Voice is constant, tone varies by situation. Most “voice” failures are tone failures, so document both.
- Give every trait a “but not” boundary, or it drifts and nobody can point to when.
- A word list of ten in and ten out is enforceable. Adjectives are not.
- Build the messaging framework from the top three objections, not from what the business wants to say.
- Publish ten before-and-after rewrites of your own copy. Writers, and AI drafting tools, copy patterns rather than principles.
Related reading
Sources
- Voice and Tone, Mailchimp Content Style Guide
- Writing Goals and Principles, Mailchimp Content Style Guide
- Branding
- Copywriting

Written by
Mara Whitfield
Brand Strategy Lead
Mara Whitfield leads brand strategy at ThisCom, helping small and medium businesses build distinctive brands and consistent digital presences that earn trust and stand out.
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