Hi, can I ask a question about tax whilst working abroad please?

Firstly, you are unlikely to be considered resident for tax purposes in Australia or Singapore because you don't spend more than 183 living in either country.

As a result, you will continue to be considered resident for tax purposes in the UK, even though you will spend 182 days in the UK during the 2012/13 tax year. This is because you would be considered as ordinarily resident and domiciles in the UK: it is where you normally live and will return to after your temporary absences abroad.

Therefore you should continue to be taxed in the UK. It will therefore be easier for you to remain on a UK-based contract if you can.

As a result, you should not be paying any Australian or Singapore tax on your income earned.

In the event that you are placed on non-UK contracts, your employer must have regard to your tax situation and arrange PAYE payments to HMRC not the Australian tax authorities.

You can introduce a claim for relief from Australian tax by contacting
the Commissioner of Taxation, Australian Taxation Office, Langton Street, Parkes 2600, New South Wales, Australia. You will first need to obtain a certificate from HMRC to confirm your tax residence in the UK.
http://www.ato.gov.au/content/61009.htm

You can introduce a claim for tax relief from Singaporean tax by contacting the Commissioner of Inland Revenue, Fullerton Buildings, PO Box 231, Republic of Singapore. You will first need to obtain a certificate from HMRC to confirm your tax residence in the UK.
http://www.iras.gov.sg/irasHome/page04.aspx?id=9128

In the event that you were to be taxed in Australia or Singapore, you should know that the UK has double-taxation treaties with these countries which permit foreign income tax to act as a credit towards your UK income tax bill.

I hope this answers your question. Please don't forget to click accept. Thanks in advance.