Credit to Jeppy on MSE - I have copied this from there;
At the moment there is a glitch so be quick - all the codes are working on one order
500 points - I think this has to go first - doesnt always work
Above are £5
XX-SCAW3 - £10
At least 4 of these are working at the moment on the one order!! If you can get the points one to work it could be the equivalent of a free order!!
Enter one at a time.
Not sure if you need to spend £50 or £60 , sometimes the full price sets in at other times its the sale price.
Add an item from the Clearance Section for free delivery - there are items for less than the standard £3.95 delivery charge.