What is the bus fare from Manchester to London?

The fares vary greatly on the company used and also how far you book in advance. It's near impossable to use buses for that journey, but coaches do frequently operate that route.

The two companies are Megabus and National Express. Megabus is more of a budget company.

I have attached a link to the two websites for more information and fares...

May I also suggest taking the train, which would be more comfortable and considerably quicker (takes around 2 hours). Fares start at £18 return, if of course you book in advance. Fares become availiable 12 weeks prior to the date of travel. I've also attached Virgin Trains website, where you can purchase tickets from.