MED1 - how does does the benefit appear ?

Quick question - I have checked the revenue website and also oasis, but I'm still not sure what the story is when submitting a MED1.

Assume I send in a form to Revenue covering expenses incurred last year - I think my relief is granted by modifying my tax credit or cut-off for *this* year. Is this correct, or do I get a cheque back, or does the relief/benefit get offset against my final liablility for last year when I submit my return ?

Also, as I understand it, the MED1 can be submitted totally independent of my actual return for last year. It can be submitted at any time after the year end.

Any advise appreciated.

z

Last year, we got a cheque back, but the amounts involved were fairly big (4-figure sum).

re: Med1 form

Have done this for the last few years and you do get a cheque back for the amount owed.