In Ireland the PPS Number ( Personal Public Service Number) is a personal reference number that allows you to gain access to social welfare benefits and services in Ireland.
It is the equivalent of the National Insurance number in the UK.
Without a PPS number you will not be able to get a job or any state Benefits. It is used for Taxation purposes too. You also need a PPS number to get an Irish driving licence.
It used to be known as the RSI number

You cannot apply for a PPS Number before you move to Ireland. You must be already living in Ireland in order to get your PPS Number. The nearest Social Welfare office will assist you with the registration process. You will be asked to produce evidence of identity and residence in Ireland. If you are not Irish, you will need to produce the following documents when getting a PPS number: a) Your passport or national identity card Or Your Immigration Card b) Evidence of your Irish address, such as a household bill (ESB, telephone, gas, etc.) in your name.

Do not pay anyone to apply for a PPS number for you - it is a simple process that is free to everyone.

For more information You can phone the Department of Social and Family Affairs at (01) 704 3236

Tip: If you are moving to Ireland you should be able to keep your existing Credit Cards - just tell the providers that you are moving. You will need some way of paying it off - i.e a current internet bank account in the country you came from. This should not be a problem - it might be a good idea to get one set up before you move. It will be easier to pay off any old bills in your previous address.