What's the real difference between local and national SEO?
Think of it in terms of what the searcher wants. National SEO targets people looking for general information, like a blog post on 'how to service a boiler'. They could be anywhere in the UK. Local SEO is for the person typing 'emergency boiler repair Dundee' into their phone at 10pm. They don't need an article; they need a phone number for a reliable person who can get to them quickly.
Because the intent is different, the ranking factors change. National SEO often chases links from big news sites and building broad authority. Local SEO cares more about different signals: your proximity to the searcher, the quality and number of your Google reviews from local customers, and having your business name and address listed correctly in local directories. It's less about being a national brand and more about being the best choice on your patch.