How to write a specification for your patent application

A specification describes what your invention is and how it works in detail. It's important to capture and structure your specification correctly, as there are strict requirements to follow. Here's what you need to include.  

Get started with a template

You can download a template with the page layout already set up to help guide you along the way.

To help you get a clear idea of what a successful specification looks like, we've provided examples of different invention types and specifications below.

What to include and how to include it

1. A description of the invention

A description describes your invention in detail. All standard, provisional and international applications must include a description that:

  • Fully describes your invention so that others could reproduce it from the information given
  • Describes the best method of how to use your invention.

The list below shows the titles, sub-titles and order that should be used within the description. The titles in bold should be included in the application. If, due to the nature of the invention, the section titles aren't suitable, alternative titles may be used.

  • Title of invention or title
  • Technical field or field
  • Background art or background
  • Summary of invention or summary
    • Technical problem
    • Solution to problem
    • Advantageous effects of invention
  • Brief description of drawings (if applicable)
  • Description of embodiments
    • Examples
    • Industrial applicability
    • Reference signs list (if applicable)
    • Reference to deposited biological material (if applicable)
  • Sequence listing free text (if applicable)
  • Citation list (if applicable)
    • Patent literature (if applicable)
    • Non-patent literature (if applicable).

Paragraphs should be left aligned. Each paragraph number should align to the first line of each paragraph.

Your description must not include drawings but may include chemical or mathematical formulae and/or tables where necessary.

The section titles and titles within the description shouldn't be numbered.

2. Statement of claims

The statement of claims tells us exactly what you've invented. You'll need to precisely define your invention or inventive concept.

The claims define the protection your patent provides. When we examine your application, we'll use the statement of claims when we compare your invention to others.

This is a requirement for standard applications, and optional for provisional applications.

A claim should:

  • Be clear and concise
  • Be written in plain English
  • Be written as a single sentence
  • Clearly define your invention
  • Distinguish your invention from other inventions
  • Focus on the features of your invention, rather than a statement of benefit or speculation
  • Set out all the essential technical features of your invention or inventive concept, and the way they interrelate to make it work
  • Be consistent with and supported by the description.

Types of claims

An independent claim is one that doesn't refer to any other claim. It defines the features that are essential to the invention or inventive concept.

A standard patent application can have more than one independent claim but they must all relate to the same invention or inventive concept.

A dependent claim references one or more previous claims.

You should ensure that the introduction of each dependent claim refers to the earlier claim. You can do this by repeating the introductory words of the independent claim and referring to the claim by number. For example, ‘The table leg of claim 1 further characterised by...’.

The extra features specified in dependent claims would be those that you consider desirable or optional to your invention or concept. They can be a safeguard in case the invention in the independent claim isn't new, or the independent claim is shown to be invalid after a patent has been granted.

They may also be of value when negotiating a licence agreement with a manufacturer.

How many claims should I make?

You can make as many claims as you like, but they must be reasonable and define only one invention or inventive concept.

If you try to claim too much, it may be difficult to obtain or defend those rights. If you claim too little, you may miss out on valuable opportunities.

If you make more than 20 claims, you'll need to pay an additional fee for each additional claim.

  • Claims must commence on a separate page to the description and follow the description
  • Each claim must be numbered sequentially, beginning with "1"
  • Each claim number should align to the first line of each claim
  • The first line of text of each claim should be right-indented with respect to the claim number by at least 1 cm, allowing for a clean separation between the first line of the text of the claim and the claim number
  • Claims must not include drawings but may include chemical or mathematical formulae and/or tables where necessary.

3. Summary abstract

An abstract is a brief summary of your invention that will help the reader to quickly identify key features.

  • Abstracts should be between 50   150 words
  • Abstracts must not include drawings but may include chemical or mathematical formulae and/or tables where necessary
  • Abstract pages should not be numbered.

4. Drawings

You should use drawings wherever possible to help describe your invention. Drawings must be in black ink and drawn using either drafting instruments or computer software.

Significant features of the drawings should be clearly labelled by number(s) and described in the body of the specification.

  • Drawings must commence on a separate page after the abstract
  • Images and drawings must be executed in durable, dense, dark, uniformly thick and well-defined, lines and strokes without colouring
  • Greyscale images shouldn't be used as information is lost when scanning them or converting them to black and white
  • Each drawing or figure should be numbered separately and labelled by a sign to indicate that it's a drawing
  • Drawing pages must be numbered showing the page number and total page numbers, for example 1/2, 2/2
  • Drawings must not be included in the description, claims or abstract
  • Drawings must not contain a frame surrounding them
  • A drawing must not include text, other than a word or words necessary to the understanding the drawing.

5. Gene sequence listings (if required)

A sequence listing is an optional document that contains nucleic acid and protein sequences. This is helpful for some biotechnology or medical inventions where:

  • Sequences are relevant for describing the invention
  • Sequences form part of how the invention works.

For example, patent applications for transgenic plants, engineered proteins, and diagnostics often include a sequence listing.

How to format your specifications

It's important to follow the below formatting rules as they'll help ensure that your specifications meet the Australian requirements. They'll also be suitable for overseas patent offices.

Our specification template contains the correct page layout and styling, so consider using it as your base.

  • The size of the sheets must be A4 (21 cm x 29.7 cm)
  • Landscape orientation must not be used unless there are drawings, tables, chemical or mathematical formulae that wouldn't fit in a portrait orientation
  • Pages must be printed on one side
  • Pages of a specification (except the drawings) must be sequentially numbered beginning with '1' on the first page of the description
  • Page numbers must be centred at the top of each page and should be located 0.5 centimetres from the margin
  • Drawing pages should be numbered using the format 1/n, 2/n...n/n (where 'n' is the total number of drawing sheets)
  • Paragraphs in a specification may be sequentially numbered from the first paragraph of the description, contained within brackets beginning with '[0001]'
  • Paragraphs should be left-aligned. Each paragraph number should align to the first line of each paragraph
  • The space between the paragraphs should be at least twice the intra-paragraph line spacing
  • Line numbering shouldn't be used
  • All pages should contain only one direction of text
  • Text must be set at one and a half line spacing
  • Handwritten text paragraphs or annotations shouldn't be used
  • All characters should be a solid dark colour on a white background.
  • Each sheet of abstract, description and claims must have the left-hand margin set to at least 2.5 cm and all other margins set to at least at 2 cm
  • Each sheet of drawing must have the top and the left margins set at least at 2.5 cm, right margin set at least at 1.5 cm and bottom margin set at least at 1 cm.

All text must be presented in letters the capitals of which are not less than 0.21 cm high, in a dark colour and be indelible. As a guide, a minimum font size of 12 points is acceptable.

The fonts should preferably be in solid black.

The preferred fonts are:

  • Mono spaced family: OCR-B, Courier New, Free Mono
  • Serif family: ITC Officina Serif, Times New Roman, Free Times
  • Sans serif family: Verdana, ITC Officina Sans, Arial, Helvetica, DejaVu Sans.

Narrow and cursive fonts shouldn't be used.

  • Bold and italic styles, and underlined text shouldn't be used.
  • Tables, chemical formulae and mathematical formulae should be separated from text paragraphs (see Appendices VI to VIII)
  • Tables, chemical formulae and mathematical formulae should be separated above and below text paragraphs by a clear space of at least 1 cm across the width of the page
  • Tables should contain one direction of text
  • Tables should have borders. The borders should be solid lines having a minimum thickness of 1.5 points
  • Each Table, formula or mathematical equation should be labelled by a sign to indicate that it's a table, formula or equation. For example, 'Fig. 1, Table 1, Math. 1, Chem. 1, Formula 1, Equation 1 or Compound 1'.

Terminology and signs

  • Units of description must be expressed in terms of the metric system or, if first expressed in other terms, must be expressed also in terms of that system
  • Temperatures must be expressed in degrees Celsius or, if first expressed in another manner, must be expressed also in degrees Celsius
  • To indicate units of measurement, the rules of international practice must be observed, and
  • In chemical formulas, the symbols, atomic weights and molecular formulas in general use must be employed, and
  • Other terms, signs and symbols that are generally accepted in the art to which the document principally relates must be employed, and
  • The beginning of any decimal fraction must be marked by a period, and
  • Units, signs, symbols and other terms must be used consistently.

Scandalous matter

A patent request and a complete specification of a complete application must not contain or consist of scandalous matter.

Need help with your patent application? 

If you're a small to medium business, you could be eligible to use our free patent case manager service.

If you'd like tailored advice or hands-on help with your application, you should consider engaging an IP attorney.

Apply for a patent case manager   Engage an IP attorney