Ok thanks,done a search after posting this and seen other posters with same question, have to wait until im married so. If my fiance gave up work after we get married, would I be able to claim all her tax credit?
You could claim her personal tax credit but not her PAYE tax credit which is employment specific. You only go on joint assessment from the start of the tax year following marriage, but you may be entitled to a review of the year of marriage which may result in a reduction in some of your tax.
You would also be entitled to a higher standard rate band than you have at present.
You could also claim the Home Carer tax credit for your (new) wife as a stay at home carer for the child.