When you have missed the chance to renew your domain, there is a big possibility that your domain will be registered by companies whose business is to buy available and expired domains to sell them for a higher price when another requires those domain names, usually the previous owner. You do not have to worry about your website content and files though, as it is only the domain name that has been acquired.
The only way to avoid this is to renew your domain before it expires. But if you missed the renewal, here are some options to retrieve the ownership of your domain:
1. Buy the domain back from the new registrant but expect a higher price.
2. You may go to https://www.auda.org.au/ to go against the new registrant. This site is the registration authority for the .au domain space.
If you opted not to do the above methods, you may have to wait until the domain expires again, which most likely will be in two years since the new registrant might drop the domain quickly if no one is interested in buying it from them.
Alternatively, you can register a new domain which is almost identical to your previous domain. Example, if the domain name is blue.net.au, you may register blue.org.au. If it is blue88.com.au, you may register blue-88.com.au as long as it is available. We can get your website to work on the new domain within minutes. Once completed, you do not have to pay SEO companies to submit your website to search engine companies. Below is a good guide about this.
You may submit your website to search engines in this link.
http://www.entireweb.com/free_submission/
Of course, it is always better to monitor and make sure your domains are renewed properly and on time. We hope that this information may provide useful to you in the future.