on Just Publishing Advice:
The copyright page of your book is an essential element you should include when you publish a new book or ebook.
Is it a legal obligation? No. Legally you own the copyright of your book as soon as you write it.
But it is always better to include at least the essential information to reinforce your ownership and copyright and dissuade any infringements of your rights.
If you are a new self-publishing author, you might be wondering what you need to include on a copyright page. Well, relax, because it is all quite simple and it will only take you a few minutes to complete.