Prior art

You invented something last month. Then you find a five-year-old forum post from a hobbyist in another country describing almost the same thing. It feels irrelevant. Patent law disagrees.

In simple words

Everything that was already available to the public anywhere in the world before your relevant date, in any form, and which can therefore be used to argue that your invention is not new or not inventive.

Think of it as

“Has the world already seen this?”

Why it matters

Prior art is the yardstick for both novelty and inventive step. It decides whether an application survives examination, and it is the first thing an opponent or a defendant will go looking for. Most avoidable patent failures are prior-art failures.

A simple example

A YouTube video, a master's thesis in a university library, a product on sale in one shop, an expired patent from 1974, a conference abstract, a company brochure - all of these can be prior art. So can your own presentation, if you gave it before you filed.

Common mistake

Assuming only patents count. Any public disclosure counts, in any language, from anywhere in the world - including your own.

Where it comes from

Patents Act 1970 - “new invention” in section 2(1)(l); anticipation in sections 29 to 34; grounds in section 25 and section 64