Sell them on eBay - I have seen money off vouchers selling for like half the discount they give - crazy people!
Only one of the accounts has ever offered up vouchers, but they come pretty much every month so no real need to worry on that score. If I'm honest, I find sainsburys so expensive that when with the vouchers, it's not much different to the regular prices elsewhere. Plus I get vouchers for Tesco too...
Don't do it! Keep the three separate & use one until one of the others get money off vouchers in the post, use that one until one of the others gets vouchers, etc. You can get £4 off £20, £6 off 30 or £8 off £40.
Does anyone know if Sainsbury’s double up points around Christmas? Trying to work out the best way to spend mine and I’ve not had an Argos email.