Q From David Means: I sometimes read or hear the phrase done and done used to seal a business deal or bargain — usually in historical dramas. Is the repetition there merely to emphasize that the deal has been completed; or is it acknowledging that two halves of an unstated, understood whole, such as payment and delivery, will be completed? Or is this a modern affectation meant to imply Regency or Victorian language?
A Let’s take your last point first. It’s certainly not a modern invention, but a real expression of an earlier period that is now defunct. Like you, I’ve come across it on occasion. However, the Oxford English Dictionary — my usual source of information for such phrases — fails on this occasion and I can’t find another reference work that gives any details.
Hunting around in my literature database, I’ve found a few examples that suggest it might be an eighteenth-century Irish expression. Its appearances all refer to wagers. The classic case, and the earliest I’ve found, appears in Castle Rackrent by Maria Edgeworth, published in 1800: “‘Done,’ says my master; ‘I’ll lay you a hundred golden guineas to a tester you don’t.’ ‘Done,’ says the gauger; and done and done’s enough between two gentlemen.” [Tester: a slang term for sixpence; gauger: an exciseman’s assistant who checked the capacity of casks.] This book, hardly known nowadays, was an early example of the historical novel, and was set in Ireland, Maria Edgeworth’s homeland.
From these and other instances, it seems that the usual convention was that a bet was agreed on the mere word of the two principals if both said “done”. They both being gentlemen, or assumed to be such, their word was their bond and there was no question of going back on the agreement once it had been made. Hence “done and done” meant that a binding agreement had been mutually accepted. Another example is in The Virginians by William Makepeace Thackeray, dated 1859: “I’ll take your bet — there. And so Done and Done.”
I haven’t found a case in which the phrase was said in reference to a business deal, but it’s easy to see how the idea could have been extended. Though most of my few examples are Irish or British, I did find one that suggested it has also been known in the USA. It’s from The Crater, by James Fenimore Cooper, published in 1848: “Done and done between gentlemen, is enough, sir.”