Schema markup is code added to a web page that labels its content in a shared vocabulary search engines understand, so they know for certain that a set of words is a business address, a product price, an author or an event date. It is the most common form of structured data, and the vocabulary lives at Schema.org.
How schema markup works
Schema.org was launched in 2011 by Google, Microsoft, Yahoo and later Yandex as a common set of types and properties. A type is a kind of thing, such as LocalBusiness, Product, Article, Person or Event. Properties describe it: name, address, telephone, priceCurrency, datePublished. You choose the types that match what is really on the page and fill in the properties.
The markup can be written in three formats. JSON-LD is a block of code that sits apart from the visible text, which makes it easy to add and maintain, and it is the format Google recommends. Microdata and RDFa add attributes to the HTML itself. Whatever the format, the information must match what visitors can see on the page.
Search engines use the markup in two ways. It helps them understand entities and relationships, for example that your business, its founder and its reviews belong together. And for some types it makes a page eligible for rich results: star ratings, prices and stock, breadcrumbs, event dates, or a richer business panel. Eligibility is not a promise; Google decides when to show them.
Why it matters
For a UK business, a few types do most of the work. LocalBusiness or Organization markup (Schema.org type names use American spelling) states your name, address, phone number, opening hours and area served, which supports consistency with your Google Business Profile. Product markup with price in GBP, availability and reviews helps shops stand out in search and Google’s shopping surfaces. Article and Person markup make authorship clear, which supports trust on advice content.
Google changes which rich results it shows. Since 2023 it has restricted FAQ rich results to a small set of authoritative government and health sites, dropped How-to results and retired several less-used types. At the time of writing (October 2026), structured data still helps search engines and other systems read a page accurately, but adding it purely to win a particular visual feature is a bet on something Google can withdraw.
Common mistakes
- Marking up things that are not on the page. Reviews, prices or FAQs that visitors cannot see break Google’s guidelines and can lead to a manual action.
- Self-serving review stars. Google does not show star ratings for reviews a business publishes about itself on its own LocalBusiness or Organization markup.
- Conflicting plugins. Two WordPress plugins each outputting their own schema can create duplicate or contradictory entities.
- Stale details. An old address, phone number or price in the markup after the visible page changed.
- Skipping validation. One syntax error can stop the whole block from being read.
How to act on it
List your page types (home, service, product, article, contact) and decide which Schema.org type genuinely describes each. Implement it in JSON-LD, ideally generated from the same data that fills the page, so prices and details cannot drift apart. Test each template with Google’s Rich Results Test and the Schema Markup Validator, then watch the enhancement reports in Search Console for errors as Google recrawls.
Local businesses should start with LocalBusiness schema on the home or contact page, and shops with Product schema. If you want it planned and built across a whole site, my schema markup and structured data service covers the audit, implementation and testing.