Choosing a domain name and extension

For a business trading in the UK, .co.uk is still the default choice and the one most UK visitors expect. .uk is the shorter second-level version of the same namespace and works fine as a primary name, and .com is worth having if you sell overseas or ever might. Pick one name to be the real one, register the obvious near-misses only if the renewal cost is worth it to you, and get the registrant details right at the point of registration, because that is the part that is genuinely expensive to fix later.

This guide picks up from a point where you know roughly what you are building and where you will host it. You do not need hosting in place yet to follow it, and you do not need to be a Hostworld customer.

Before you start

Have these settled before you type anything into a search box:

• Who legally owns the domain. This should be the person or company that should control it: not an employee, not your web designer, not an invented trading name that does not exist as an entity. Registering a client's domain in your own name creates an ownership problem that surfaces years later when someone leaves.
• A contact email address that outlives staff and suppliers. Renewal notices, registry verification emails and account recovery all go to that address. If it belongs to a person who might leave, or to an agency you might stop working with, change it now.
• The renewal price, not just the first-year price. Some registrars sell a 99p first year and then charge £12 or more at renewal. Check the second-year figure before you commit, particularly if you are registering several variants.
• Five minutes for a trademark check. "Available" and "safe to use" are not the same thing. Nominet operates a Dispute Resolution Service for complaints about .UK registrations, and a domain that mirrors someone else's trademark is a domain you can lose.

The thing most likely to bite you is not the name. It is the registrant details. Nominet's Data Quality Policy requires both the registrant name and the registrant address to be verified against a third-party data source. Where Nominet cannot validate them, it asks the registrar to have them verified, and a domain that does not complete verification within 30 days is suspended and can no longer be renewed or transferred. Nominet's completeness rules include a registrant name of at least four characters with at least three letters, and a first line of address that is not only a number. Verification emails come from [email protected]. Put a real name and a real address on the order form.

Step 1: Decide what the name actually has to do

A domain has to survive being said out loud on the phone, typed from memory, and printed on a van. That rules out most of the clever options. In practice:

• Short beats descriptive if you have to choose. People remember short.
• Avoid names that only work written down, such as anything relying on an unusual spelling or a homophone.
• Hyphens are a last resort. Nominet's rules require spaces in a candidate name to be removed or turned into hyphens, one hyphen per continuous run of spaces, which is the mechanical origin of most hyphenated .uk names. That does not make them a good idea to say aloud.
• Do not encode anything that changes. A town, a year, a product line or a phone number in the domain is a rebrand waiting to happen.

Shortlist three or four names rather than falling in love with one, because availability will make the decision for you.

Step 2: Check the name properly, not just for availability

Run each shortlisted name through three checks:

1. Availability across every extension you might want, so you are not committing to a name whose .com is gone if the .com matters to you.
2. Trademarks. A search of the relevant trademark register is cheap and quick compared with a dispute.
3. History. Second-hand domains carry their previous owner's reputation. If a name has been registered before, find out what it was used for.

One point on lookups: for .UK names, a status of "pending delete" in a lookup does not mean what it sounds like. It simply means the domain is past expiry and past its initial 30-day grace period. RDAP, which is the successor to WHOIS, gives a more accurate picture than doing arithmetic on dates.

Step 3: Choose the extension

What each one signals to a UK visitor

.co.uk reads as "a UK business" to a UK audience, and it is by far the most common thing they see. Wikipedia's registry summary puts the .uk namespace at roughly 10.5 million registered domains as at January 2024, split about 9.31 million at the third level (mostly .co.uk) against 1.37 million second-level .uk. That is close to six to one. A registrar guide reports Nominet research finding that 81% of UK consumers would choose a .co.uk over a .com. We could not verify that figure on a Nominet page, so treat it as indicative rather than gospel, but the direction of travel matches what the registration numbers show.

.uk is shorter and modern, and it is a perfectly respectable primary domain. Nominet launched it as a standalone second-level extension in June 2014. The predicted stampede from .co.uk did not happen. It reads as UK just as clearly, and the only real drawback is that a caller on the phone may assume you meant .co.uk.

.com is the default global extension: a registrar guide summarising the Q4 2025 Domain Name Industry Brief puts total registrations at nearly 387 million, of which 161 million are .com. To a UK visitor it signals a larger or international organisation, not a local one. It is the right primary choice if most of your customers are outside the UK.

.org.uk is intended for charities, trades unions, political parties, community groups, educational councils and professional institutions. .me.uk is described as being for personal use. .ac.uk and .gov.uk are not run by Nominet at all and have their own eligibility rules, through Jisc and GOV.UK respectively, so they are not options for an ordinary business.

Nominet's Rules of Registration are the binding document here, and they contain separate rules for .co.uk, .org.uk, .me.uk, .net.uk and .ltd.uk/.plc.uk that take precedence over the general rules where the two conflict. If you need the exact wording, read the Nominet Rules of Registration rather than a reseller's summary. You will find pages online claiming you must be a registered UK company to hold a .co.uk. That is not the case: registration is open, first come first served. The requirement people are half-remembering is that an overseas registrant of a second-level .uk needs a UK address for service listed as the admin contact, and a PO Box is not acceptable.

On search engines

A UK country extension carries an inherent UK signal. A .com does not automatically associate with any country. That is a real but modest effect, and it is not a reason to pick a worse name. Content, links and relevance move the needle considerably more than the letters after the dot.

Step 4: Decide how many to register

The honest answer for most small businesses is: one primary, plus one or two defensive registrations, and no more.

If you are UK-focused, register the .co.uk (or the .uk) as your primary, and add the matching .com if the budget allows and it is available. Owning the matching .uk alongside your .co.uk is sensible if the name matters to you, but be clear that you have no special claim to it. Holders of a .co.uk had a temporary reserved right to the matching .uk when second-level registration launched in 2014, and that reservation period ended on 25 June 2019. Anyone can now take it.

Beyond that, defensive registration gets expensive fast and protects against very little. Buying every typo and every new extension is a renewal bill you pay forever. Pick the ones a real customer might plausibly type.

Whatever you register, choose one to be the canonical address that appears on your website, your email and your stationery, and redirect the others to it. Running two names as though both are real splits your traffic and confuses people.

Step 5: Register it to the right entity, with details that will validate

When you order a domain through our client area at portal.hostworld.uk, which is a standard WHMCS installation, the contact details on the account are sent to the registry as the registrant at the point of registration. WHMCS always uses the client's details as the registrant contact information. So the name and address on the order form are the ones Nominet will validate against a third-party source, and the ones that will get the domain suspended in 30 days if they do not check out.

Practical consequences:

• Put the company's legal name and registered trading address on the account, not a nickname and not a home address you are about to move out of.
• If you are ordering on behalf of a client, the account should be theirs.
• WHMCS does not cache WHOIS data. It queries the registrar in real time and sends any edit straight through. A registrant change you make in the client area is live at the registry the moment you submit it.

UK registration terms run from one to ten years.

The ordering trap: registrant changes and transfers

This one catches people out permanently, and it applies to generic top-level domains such as .com rather than to .co.uk. Under ICANN's Transfer Policy, a transfer is blocked if it is requested within 60 days of the creation date, and also where the registrar imposed a 60-day inter-registrar transfer lock following a change of registrant and the holder did not opt out before making that change.

So if you intend to move a .com to a different registrar, do the transfer first, then change the registrant. Correcting a typo in a phone number or updating a postal address on the existing registrant does not normally trigger the lock. Changing the registrant's name, email address or organisation does. Where an opt-out is offered it must be selected during the owner-change procedure, and it cannot be applied afterwards. The lock only prevents a registrar transfer: hosting, email and everything else keep working.

ICANN updated the Transfer Policy in February 2024, with contracted parties required to implement by 21 August 2025, and in March 2025 the GNSO Council approved 47 further recommended changes that would cut the relevant locks to 720 hours (30 days) and remove the lock requirement entirely for a change of registrant data. Those are proposals in progress. Industry estimates put them at least 18 months out, so plan around the 60-day rule today.

Step 6: Point the domain at your hosting

A domain on its own does nothing. It needs nameservers pointing at the hosting that will answer for it. Ours are:

• ns1.serverworld.uk
• ns2.serverworld.uk
• ns3.serverworld.uk
• ns4.serverworld.uk

Note that the domain is serverworld.uk, not hostworld.uk. That is correct and deliberate. Enter all four exactly as written. A single wrong character takes a site and its email offline.

If you order a domain in the same basket as a hosting product at portal.hostworld.uk, WHMCS applies the nameservers configured for that product's server automatically, so the domain normally arrives already pointed at us. Check rather than assume, and do not retype anything that is already correct. If you register a domain on its own, or you are bringing one in from elsewhere, you set the nameservers yourself: in our client area for a domain registered with us, or at your existing registrar for one that lives there. What you can do from the client area varies by registrar, because WHMCS exposes whatever that registrar's module supports, so look for the nameserver option on the domain's own page rather than expecting a fixed button.

Once the domain resolves to us, DNS records, mail routing and SSL are handled in the panel for your product: cPanel for shared, reseller and WordPress hosting, and Virtualizor for a VPS.

Step 7: Make sure it does not quietly expire

Expiry is the single most common way a working business loses its website and email, and .uk does not behave like .com.

.uk, per Nominet's registrar procedure

• A renewal can be submitted at any time up to 90 days after the expiry timestamp.
• Nominet sends a suspension notice at 30 days after expiry, saying it is still not too late to renew. In practice a suspended .uk stops resolving, so your site and email go down at day 30, not day 90.
• A cancellation warning goes out at 83 days.
• Cancellation begins exactly 90 days after expiry. Renewal attempts after that are rejected. The domain drops at expiry plus 95 days.

.com and other gTLDs

A different clock: a registrar renewal grace period, then a Redemption Grace Period, then Pending Delete for five days before the name becomes available again. The grace lengths vary by registrar and registry, so check yours rather than trusting a number you read somewhere. Redemption normally costs a recovery fee on top of the renewal, and quoted figures vary widely by registrar.

Turn on auto-renew, keep a working card on the account, and keep the contact address current. All three have to be true for auto-renew to save you.

One date for the diary: Nominet is moving .UK onto its Registry Services Provider platform on 9 February 2027, with revised policies published on 9 April 2026 taking effect at transition. Existing policies apply until then. Part of that work lets registrars choose between today's auto-delete behaviour and a gTLD-style auto-renew, so the timeline above is accurate as things stand and is explicitly in scope to change.

What next

You have a name, an extension and a registrant that will survive validation. The next step in this playbook is pointing the domain at Hostworld: setting the four serverworld.uk nameservers at whichever registrar holds the domain, and knowing what to check once they have taken effect. That is covered in our DNS guides, and the wider set of domain topics, including transfers in, lives in our domain guides.

If you are not sure which of our products the domain should land on, or you want us to confirm a registrant record before it goes to Nominet, open a support ticket and we will look at the domain with you. Tickets are logged against your account, so there is a record of what was changed and when.