Yes .. when specifically talking about the UK then ___.co.uk is still the extension people use most for local commerce.
Just be aware that there are location requirements for registering just about any ____.__.uk or _____.uk domains. Essentially you need to be a UK resident or have a business there. There are ways to get around it by paying extra for a proxy registration, but it's definitely something you should look into yourself.
Many countries have such restrictions like Canada (.ca) and the USA (.us).
When it comes to the ___.com.__ or ___.co.__ domains of different countries be very careful .. they are NOT all the same. Some are NOT even controlled by the country and could be private (like __.co.com was, although it wasn't a country code domain), so could be cancelled/stolen at any time.
So to answer your specific question about .uk domains, the answer is yes. But if you were just using that as a random example, then be warned that the answer is different for every country.