Query on transferring tax credits between spouses

If both spouses are in employment, can one spouse transfer all tax credits to the other spouse?

example: if the only tax credit of spouse 2 is the PAYE tax credit of €1,650, can this be transferred to spouse 1?

from revenue.ie

If both spouses or civil partners have taxable income, they can decide which spouse or civil partner of them is to be the assessable spouseor nominated civil partner and request their local Revenue office to allocate the tax credits and standard rate band between them in whatever way they wish. [PAYE tax credit, employment expenses and the basic standard rate band of €23,800 are non transferable.]

Just wondering if you transfer credits between spouses, can you claim back for past years?

Yes, you can. My wife and I got married in early 2008 and we only got around to sorting our credits out in late 2010.

That was a cheque which paid a few bills!

THank you, just did some changes so hopefully- a cheque would be great! Must give them a bell!