Thanks to snatch_master for posting a deal with the codes in that SkyBlu75 picked up on & posted them in vouchers, which is where I saw them. Phew - hopefully got it right now!
Smyths Toys have released discount codes that take 5 off £20 (SEP5), £10 off £50 (SEP10) & £20 off £100 (SEP20), these can be combined with lots of already discounted items & the free delivery when you spend £15 on Lego.
Had a quick look around & the LEGO Star Wars Force Awakens Millennium Falcon 75105 is on offer for £94.99, you could just use the £10 off code & get it delivered for £84.99 BUT if you add something else to your basket (doesn't have to be Lego) for £5.01 or more, you can use the £20 off £100 code. So I added the Millennium Falcon, then had a scout about & found LEGO Bionicle Skull Scorpio 70794 that was £12.99 & is now £6.49, used the code & could get BOTH delivered for £81.48.
Obviously you don't have to buy that item, anything over £5.01 will do, but that was half price, so thought it was great value on top of the falcon.
Will pop link to that & a few other cheap items in 1st post