What is a JP?
A judicial officer with limited power whose duties may include hearing cases that involve civil controversies, conserving the peace, performing judicial acts, hearing minor criminal complaints, and committing offenders. Justices of the peace are regarded as civil public officers, distinct from peace or police officers.
When you buy a house do you need a JP or Solicitor to witness your signature?
Answer: No (and JP will not do that).
When you get a loan, the mortgage document needs to be witnessed by a JP?
So who can witness a contract of sale of land or the mortgage document?
Answer: Any normal person with no special power. That is any lay‐person will do. He/she must be over 18 years of age.
Can my wife or son or very close member family members be a witness?
Answer: No. They should not as to keep it impartial.
Then when do I need a JP in the context of buying a house?
Answer: You will rarely need a JP when you buy a house.
However, on the odd occasions when the bank needs you to clarify some uncertainties then you need a JP.
For example, let's say your name is John Appleby but you sign your name as Elizabeth. The bank will be very suspicious and they will give you a chance to clarify.
You see, if your name was John Appleby, there is no law for you NOT to sign your name as Princess Diana or Adolf Hitler. If it looks strange, you must explain it in the form a Stat Dec (Statutory Declaration).
For example, John Appleby, loves his daughter Elizabeth so much, so he signs his name as Elizabeth. Once you explain that in a Stat Dec have it and witnessed by a JP, then it is acceptable by the bank.
JP can be found in many places and all Police Stations or Australia Post Office or a Library. It is a free service, so be nice to them.