Rebrands rarely fail because teams don’t care about tone of voice (ToV).

They fail because the way ToV needs to be rolled out can be underestimated. It ends up being treated as something that will ‘sort itself out’ once the visual identity is in place, but it’s actually far harder to pin down than logos, colour palettes, or typography.

It feels intangible, but in practice, ToV is often the first thing people notice about your brand, and the thing they notice most quickly when it’s wrong.

What’s changed in recent years is scale. Rebrands no longer play out neatly across a website and a handful of campaign assets. They need to be rolled out across social channels, sales decks, marketplaces, product interfaces, support content, internal comms, and increasingly, AI-generated content too.

That’s why ToV can often unravel soon after a rebrand; not because the intent is wrong, but because the execution isn’t designed to hold under pressure.

A familiar rebrand story

Some years ago, I worked on a rebrand at a financial services organisation that appeared to be a success. The visual identity was strong. The messaging felt confident. Everyone involved cared deeply about getting it right.

And yet, not long after launch, something started to feel off.

Content written by different teams began to sound noticeably different. Sales materials didn’t quite match what was on the website. Social posts felt like they belonged to a different brand altogether.

Nothing was technically wrong, but nothing felt particularly coherent either…

At the time, it was framed as a ‘messaging’ issue. And actually, one of our freelance copywriters who was trying to help implement it with some new content items really got it in the neck from senior managers when it became obvious that things “weren’t sounding right.”

With hindsight, it was something else entirely. It was a tone-of-voice problem.

More specifically, it was a problem of definition versus application. The tone had been agreed, documented, and signed off, but not embedded. People were expected to ‘pick it up’ intuitively, without enough shared reference points to do so consistently. That’s because our very expensive branding agency had supplied the scantiest of branding guidelines, accompanied by no real examples of copy whatsoever.

Where tone of voice typically goes wrong in rebrands

Most tone-of-voice issues arise from reasonable assumptions that just don’t hold up when your copywriter, content manager, and marketing team try to implement the thing.

Common issues:

Tone is defined once, then forgotten: A solid piece of work is created early on, but rarely revisited once delivery ramps up.

Large organisations that have gone through repeated rebrands (Yahoo being a commonly cited example) often struggle not because tone was never defined, but because it wasn’t sustained once attention moved on.

Abstract descriptors replace usable guidance: Words like ‘bold’, ‘human’, or ‘clear’ sound helpful, but actually mean different things to different people. This is where clearer, more practical tone guidance makes a difference.

For contrast, Mailchimp’s publicly available Voice and Tone guidance focuses less on adjectives and more on how tone should ‘flex’ in real situations.

Below is an extract from Mailchimp’s guidance, taken from its public Content Style Guide:

No surprises then, when their users see content like this:

The value here isn’t the tone itself, but the way it’s been made usable. That distinction, between defining tone and enabling people to apply it, is where many rebrands can fall down.

Too many contributors, not enough clarity: Rebrands involve more hands than usual. Without shared reference points, variation creeps in fast.

This becomes particularly visible in fast-scaling organisations. Uber’s post-rebrand period is often referenced as a moment where tone varied widely across markets; not through neglect, but through sheer volume and decentralisation.

Ownership becomes unclear after launch: Once the rebrand is “done”, tone slips between teams with no one actively stewarding it.

Even organisations with strong editorial standards aren’t immune. The BBC, for example, maintains clear overarching principles, but tone can still vary significantly by department and platform… largely because ownership is shared, not centralised.

Speed overtakes consistency: Under pressure, people revert to what feels familiar, not necessarily “what aligns”.

High-pressure rebrands often expose this tension. Meta’s early post-rebrand communications showed how quickly tone can fragment when speed and volume take precedence over consistency.

None of these issues are dramatic in isolation, but together they quietly erode coherence.

Tone of voice in the age of AI

One of the biggest differences between rebrands then and rebrands now is volume.

Due to the way it can be used to create and edit content, AI has basically exposed even more ToV problems. For example, if a brand’s tone relies on instinct, individual judgement, or a loosely worded set of principles, it won’t survive automation. That’s because AI will simply scale whatever clarity (or ambiguity) already exists.

And this is where many rebrands can come unstuck.

ToV is defined once, often ‘beautifully,’ but not translated into something that’s usable day to day
Writers, marketers, sales teams and customer support staff are left to interpret it for themselves
AI tools are then introduced into that same environment, amplifying inconsistencies rather than resolving them.

When tone is treated as a static artefact (a PDF, a workshop, a slide deck), it becomes disconnected from how content is actually created.

And once that happens, the drift is inevitable.

Brands that manage to implement and embed ToV well tend to do one thing differently. They treat tone of voice as operational, not ornamental; something that needs reinforcing, applying, and revisiting long after the rebrand has launched.

What actually helps tone stick during a rebrand?

There’s no single fix for tone-of-voice inconsistency, but there are patterns that can be adopted within your teams that can help. ToV tends to hold when:

Guidance is grounded in real examples, not just principles
Expectations are reinforced after launch, not just before
Tone is embedded into everyday workflows, not separated from them
People are given permission to apply judgement, within clear boundaries.

ToV isn’t meant to make everything sound the same or uniform; it’s there to make everything sound like it comes from the same place. When that balance is struck, tone becomes something teams lean on… not something they worry about getting wrong.

The TL;DR

Tone of voice doesn’t fall apart because teams aren’t talented, aligned, or well-intentioned. It falls apart when it’s not given the same structural support as other brand assets.

Rebrands are intense, time-pressured moments. Decisions are made quickly. Content is produced at speed. And once the launch is over, attention moves on.

So, if tone of voice hasn’t been embedded into how people work (not just what they’re told), it starts to erode.

The irony is that tone of voice isn’t fragile. It can flex, evolve, and adapt across channels without losing its core. But only if it’s treated as a shared asset, not a creative afterthought.

Get that right, and tone becomes one of the most stabilising forces in a rebrand.

Get it wrong, and it’s often the first thing audiences sense, even if they can’t quite put their finger on why…

FAQs: Tone of voice in a rebrand

Tone of voice often goes wrong because it’s defined once and then left unsupported.
Without clear examples, ownership, and reinforcement across teams, consistency quickly breaks down — especially during fast, high-volume rollouts.
Common causes include too many contributors, unclear guidance, lack of ownership, and treating tone as a one-off deliverable rather than something embedded into daily content creation.
AI doesn’t create tone issues — it scales existing ones. If a brand’s tone isn’t clearly defined and operationalised, AI tools will amplify inconsistencies rather than resolve them.
Tone of voice ownership usually sits with brand or content leadership, but responsibility needs to be shared.
It works best when tone is clearly documented, practically applied, and reinforced across teams that create content day to day.