To not matter in the slightest; to be totally unimportant. Primarily heard in UK, Australia. It doesn't matter tuppence how you get it done, just make sure the deed to that estate is in my possession within a fortnight! She doesn't come from an upper class background, but it wouldn't matter tuppence whether she were the Queen of Sheba or a beggar in the street: I love her, and that's all I care about!