A four-week TV ad push breaks on February 26 and will account for £3m of the spend.
The company claims one in 10 of Britain’s poster sites will be dedicated to the campaign in the run up to the special day on Friday March 21.
It is also linking up with The Sun and Take a Break magazine to generate publicity.
Special packs of all Kit Kat variants will go out to the trade from Monday (February 10) with consumers being offered the chance to win one of 10,000 break kits. There will also be £50,000 of cash prizes for retailers