The term patent specification or “spec” is sometimes used synonymously with patent application, but patent specification refers to the specification of the patent as granted. Having initially published a patent application as part of the patent prosecution process, the patent, if granted (and as amended) is published as the Patent Specification. Depending on how the prosecution process has gone, the published specification may be exactly the same as the application, because the examiner granted it as originally written, or it might have undergone changes as a result of negotiations between the examiner and the applicant.

Whether you’re working with a patent attorney in the UK or elsewhere in the world, it’s likely that they will discuss one or more drafts of the patent specification with you so that you and they are happy that it describes your invention comprehensively before they submit it, with your application, to the Patent Office.