Heard it on Behind the Grammar (a blog and podcast with which I have fallen instantly in love) and confirmed via Google: Penguin usually requires you to have representation to submit. Until October, they’re opening up to unagented manuscripts!
If you’ve got a manuscript in a drawer, you have less than a month to blow the dust off it and get it over there.
- How to Format a Novel Manuscript Properly (writinghood.com)
- Penguin boss has no problems with ebooks (guardian.co.uk)