Copyright’s 10% rule: is it a thing?

In this alert, we explain how you may avoid an allegation of copyright infringement by not copying a “substantial part” of another creator’s work, and outline how the “fair dealing” exceptions may help to keep you out of copyright hot water.

A question we are often asked is: “is it true that I can copy anything as long as I change 10% or 20% of it?” 

The short answer is no. Unfortunately, the copyright law in Australia is complex and nuanced, and it is not so straightforward to avoid a claim of copyright infringement. 

Generally, you can infringe another creator’s copyright if you copy or use the whole, or a substantial part of, an original work without permission. 

It may be easy to work out whether the whole of an original work has been copied. But what is a substantial part? The answer to that question tends to be more qualitative than quantitative. 

When it comes to what is a substantial part of a copyrighted work, the more recognisable examples are perhaps best laid out in music copyright cases. 

As early as 1934, Paramount Film Service was found to have infringed the copyright of Hawkes and Son (London) by reproducing 20 seconds of the four-minute march, “Colonel Bogey”. Despite the fact that the quantity or length of the portion reproduced was small when compared with the length of the original, the part taken was substantial as it was clearly recognisable and formed a “vital and essential” part of the Colonel Bogey work. 

Similarly, Aussie band Men at Work were found to have infringed copyright owned by Larrikin Music Publishing, the publishers of the Australian folk song ‘Kookaburra’. Men at Work were found to have copied the main melody of ‘Kookaburra’ as a flute riff in their 1981 song, ‘Down Under’. Despite the riff only forming a small part of the overall ‘Down Under’ work, the melody was considered a substantial part of the original work. 

If a substantial part isn’t merely about quantity, what is it about? 

The legal test is whether there is objective similarity between the two works. The test is whether the part taken is a recognisable or distinctive portion of the original. Is the part taken essential or material to the original? 

These are important considerations. The substantial part test applies across all copyrighted works, not just to music, so these factors may look different across different copyrightable works. 

What does this mean? 

If you have only changed 10% of an original work, chances are there will be objective similarity and consequently, a substantial part may have been copied. At the end of the day, it comes down to a qualitative analysis.  

Are there any exceptions?

Yes. In Australia, the Copyright Act 1968 (Cth) allows an exemption for ‘Fair Dealing’ when the copying is for a permitted purpose. Those permitted purposes are: 

  • research or study;
  • criticism or review;
  • reporting news;
  • professional advice given by a legal practitioner; and 
  • parody or satire. 

The Fair Dealing exemption isn’t a catch all, however; to come within the exemption, the dealing still has to be fair. 

In relation to the research and study exemption only, a ‘fair’ amount to copy is considered to be up to 10% or one chapter, in most circumstances. Maybe this is where the confusion around the 10% rule comes from… 

What next?

There are no bright lines when it comes to the question of copyright infringement, and the substantial part test can lead to many different outcomes depending on the original work, the new work and many other surrounding circumstances. 

If you have created a work that re-uses another creator’s work, or even takes inspiration from it, or if you think your copyright has been infringed, please contact our Intellectual Property, Technology and Cybersecurity Team for an assessment of your case.