You can come to the UK for an extended holiday for up to two years and can take up any form of work.
You will be expected to be on holiday for at least part of your time in the UK over two years.
You should have planned your employment so that it is an integral part of your working holiday. For example, you may have decided that you wish to spend some time in London and so also wish to find work in London.
You should be single, or are married to someone who also qualifies as a working holidaymaker and wish to both be working holidaymakers.
You do not have any dependent children who are aged five years or over, or who will be five before the end of the two years as working holidaymaker.
You should have enough funds to support yourself until you find work without requiring public funds. You should probably have enough money to support yourself for the first month.
You are able to pay for a return ticket or have at least enough money to go onto another destination.
You intend to leave the UK at the end of your working holidaymaker status.

If you decide to stay longer while you are in UK, you can take up employment on a Work Permit if you are eligible under the immigration rules at that point in time.