The short answer: use .co.uk if you trade mainly in the UK, register the .uk alongside it, and buy the .com only if you can get it at a sensible price.
The longer answer depends on who your customers are and what you’re protecting against — so here it is properly.
.co.uk
Still the default for British businesses, and still the one UK customers expect. It signals unambiguously that you’re a UK company, which matters more than people assume: for services where locality is relevant — trades, professional services, anything involving a visit or a UK contract — it’s a small trust signal that works in your favour.
It’s also, in practice, the extension most UK customers will type or assume.
Use it as your primary if your customers are predominantly in the UK.
.uk
Introduced in 2014 as a shorter alternative. Adoption has been steady rather than dramatic, and it has never displaced .co.uk as the expected default.
Its real value for most businesses is defensive. If you own yourcompany.co.uk and somebody else registers yourcompany.uk, they have a domain that a meaningful proportion of your customers might reasonably believe is yours — with the obvious potential for confusion, misdirected email or worse.
Registration is inexpensive. Relative to the nuisance of not having it, it’s among the cheaper pieces of insurance available.
Register it if you hold the matching .co.uk. Point it at your main site rather than running two separate ones.
.com
The global default, and the one people type when they don’t know. Worth having if you trade internationally, sell to overseas customers, or want the most recognisable version of your name.
The difficulty is availability. Most short or generic .com domains were registered decades ago, and acquiring one from an existing holder can run to four or five figures. That’s occasionally worth it and frequently not.
Register it if it’s available at standard price, or if international customers are a real part of your business. Don’t pay a large sum for it purely because it feels more professional — for a UK-focused business, .co.uk does that job.
.org.uk and .org
Conventionally used by charities, membership bodies, clubs and non-profits. There’s no restriction preventing a commercial business from using .org, but doing so tends to confuse people rather than help. If you’re a charity or a member organisation, .org.uk reads correctly and is worth having.
The newer extensions — .io, .ai, .agency, .london and the rest
These can work, with caveats worth understanding.
They’re most successful where the audience already recognises the convention — .io among software companies, for instance. Outside those contexts, they create friction: people mistype them, default to .com out of habit, and occasionally doubt them.
Two practical warnings. First, pricing on many of these extensions is materially higher at renewal than at registration, and increases have been imposed at short notice on some. Second, country-code extensions used as branding — .io, .ai, .co — remain subject to the policies of the country that owns them, which can change.
If you use one, own the .co.uk as well. It costs little and gives you somewhere to go.
How many should you actually own?
There’s an entire industry built on selling businesses domains they don’t need. A sensible baseline for most UK companies:
- Your main extension — usually .co.uk
- The matching .uk — defensive, cheap, redirected
- The .com if reasonably priced
- One or two obvious misspellings, but only if your name is genuinely easy to get wrong, and only if you’d be exposed by someone else holding them
Beyond that, you’re usually buying peace of mind rather than protection. There are infinite possible variations and you cannot own them all. The exception is where a specific lookalike domain has already been registered by someone else and is being used to intercept mail or impersonate you — that’s a live problem rather than a hypothetical one, and worth addressing directly.
The mistake that actually costs money
Not the extension. The registration details.
A business with one correctly-registered .co.uk, owned by the company, with a monitored contact address and a renewal someone is accountable for, is in a considerably better position than a business with fifteen domains scattered across four registrars in three people’s names.
Extensions are a marketing decision. Ownership is the one that bites.
Not sure what you currently hold?
A portfolio audit establishes exactly which domains your business owns, who they’re registered to, and which gaps are worth closing. We’ll also tell you which ones aren’t worth the money — that’s part of the point.
Call 01202 835235 or email contact@domainwarden.co.uk.