I created an account- not sure if it's necessary to get a free mug. Spend £20 or more and get a free mug. The mug is £3.50 usually and has to be added to your shopping cart. You then type in MUG in redeem code at checkout and mug price will be taken off.
When I did my order I bought the £20 coffee gift box which includes 9x50g jars - You can pick your own flavours. I also added the mug totalling my order to £23.50. At checkout I used the redeem code MUG this took the price of the mug off to £0.00 and my order went down to £20