Many of you will probably be aware of this already, but if your wife earns less than her personal tax allowance some of her allowance can be transferred to you, meaning you have a higher personal allowance and you could save tax. The same rule applies should your wife be earning above the threshold and you are not.
It can be backdated, so if you haven’t been doing it, then you could have a small windfall.
More information here, from HMRC:
Or here, from YourMoney.Com: