Unless you're a British citizen moving back home from Australia, you'll need to obtain a visa if you're planning to live in the UK for longer than six months or wish to work. However, you can import your personal belongings into the country tax-free by completing a Transfer of Residence Relief (ToR01) form, although, to be accepted for this, you must fulfil the following criteria:
You're returning to the UK as your usual place of residence;
You've been living outside of the country continuously for at least twelve months;
You've owned the items in your shipment for at least six months before importing;
You didn't buy or receive any of the goods you're shipping from duty or tax-free schemes;
You'll be keeping all the items for personal use and won't sell, hire them out or give them away for at least twelve months after importing;
If you qualify for tax relief, then you can't ship your personal effects to the UK earlier than six months before or later than twelve months after your arrival.