To avoid repeating this a couple of thousand times:
If you leave halfway through the year you are entitled to allocate any unused credits against your PAYE taxed income.
This is done in two ways.
The Tax year is Jan-Dec. If you request a balancing statement (P21) for the previous tax year Revenue will automatically allocate any unused credits against your PAYE Tax and issue the refund. If you are set up with Revenue online service and have registered a bank account (see seperate sticky on how to register to claim credits you may be entitled to) then the refund will hit your account in a few working days. If you do not have a bank account it will take a few weeks for the cheque to issue from Ennis.
If you are impatient you can send a letter to your local Revnue district outlining that you are leaving with the intention that you will not be resident the following year and you wish to apply the provisions of S 822 TCA to apply split year relief from the date you are leaving. This means that you are leaving and you wish to be assessed as non resident from the date of departure. As such they can allocate the credits for the rest of the year to your account on receipt of this letter.
Hope that helps. If you come back the following year it does not affect the application of S 822 as you have left with the intention of being non resident the following year- whether you are subsequently or not does not affect the application of the relief.
EDIT I have deleted a lot of peoples responses looking for personalised tax advice.
Read the charter. No.
Thread locked as a result - General advice only.