The two arrangements produce a similar book by different routes, and the right choice depends far more on what you want afterwards than on the writing itself.
The four real differences
| Ghostwriter | Co-author | |
|---|---|---|
| Cover credit | None; the book is yours alone | "with" or "and" on the cover |
| Copyright | Assigned to you in full | Usually shared, or split by contribution |
| Payment | Fixed fee, milestone-based | Lower fee plus 10–50% of royalties |
| Control | Yours entirely | Shared; disputes need a mechanism |
| Typical upfront cost | £5,000–£20,000 | £2,000–£10,000 |
When ghostwriting is right
The book's job is to build your authority. A business book that generates speaking invitations and consulting enquiries needs to be unambiguously yours. A co-author's name on the cover dilutes exactly the signal you are paying for.
It is your life story. Memoir with a second name on the cover reads oddly unless that person is part of the story.
You want certainty. A fixed fee is a known cost. A royalty share is an open-ended commitment on a book whose sales you cannot predict.
When co-authorship is right
The writer brings genuine subject expertise. If they are contributing knowledge rather than only craft, crediting them is honest and usually improves the book's reception.
They bring an audience. A co-author with a platform in your subject is providing distribution, and a royalty share is a rational way to pay for it.
Cash is tight now. Trading a lower fee for a royalty share moves cost from today to later. It is genuinely cheaper if the book sells modestly, and considerably more expensive if it sells well.
The maths of a royalty share
Consider a £4.99 eBook earning £3.29 net, with a co-author on 30%.
- 1,000 copies: co-author receives £987. Ghostwriting at £9,000 would have been worse.
- 10,000 copies: co-author receives £9,870. Roughly break-even.
- 50,000 copies: co-author receives £49,350. Ghostwriting would have been five times cheaper.
The break-even sits around 9,000 to 12,000 copies for most trade non-fiction. Below that, sharing is cheaper; above it, a fixed fee is. Since most self-published books sell under 1,000 copies, co-authorship is financially rational for the majority — which is exactly why writers offering it tend to want it on the books they think will sell.
The hybrid most people actually choose
A fixed fee for the writing, no royalty share, and a discreet acknowledgement rather than cover credit. The acknowledgements page thanks the writer for "editorial and writing support", which is honest without diluting the authorship signal. Most professional ghostwriters accept this happily, and many prefer it to a royalty share on an unproven book.
Whichever you choose, settle these in writing
- Copyright. Who owns it, and when it transfers. This is the clause that causes litigation.
- Credit. Exact wording and placement — cover, title page, acknowledgements, or nowhere.
- Derivative rights. Audiobook, translation, film. A co-author with unallocated derivative rights can block a deal years later.
- Final say. Someone must be able to break a deadlock. Usually that is whoever is paying.
- Exit. What happens if one party stops. Who owns the partial manuscript, and on what terms.
Ambiguity here is never neutral. It resolves in favour of whoever is more willing to argue, which is rarely the person who commissioned the book.