You can share your unused tax credits and/or bands to maximise take home pay.For example,if one of you was on the lower rate band and one was on the higher rate,you could transfer any unused band from the lower paid partner to the higher paid partner to move some of their income from 40% to 20%.
If you are not registered to PAYE anytime,do so,as you can then do this yourself.
If you post up your two salary levels,someone here can tell you if you can take advantage of this.