It was always 1 Mile per £ at £300 and above.

However, the BA Travelex rate was very poor and hence I stopped getting currency this way several years ago. The £4.50 fee charged by Barclays also had an effect!

There used to be a work-around which involved going through the BA-flavoured special website for one of BA's old car hire partners, whereby you got Travelex's 'normal' rate AND BA Miles, but that stopped when BA dropped them as a car hire partner.

Having done the 'get-cash-out-then-go-to-M&S' method for a couple of years, I now have a FairFX card.

Excellent (Mastercard) exchange rates, easy, quick and free loading, no fee for purchases, £5 Quidco and only 1.5 Euros for cash withdrawals or to empty the card again via a cashpoint in the UK.