A reader wrote in by email asking "whether it’s fine to submit a book proposal, or manuscript, to multiple publishers at once?"
I wrote the following here back in 2015:
4. Is it acceptable to send out proposals to multiple presses at the same time? Is it a good idea? I know Leiter had a thread on this a while back and absolutely no one could agree.
I struggled (as Sam did) to find good answers to this online, but actually in my experience it has a very straightforward answer: each publisher has their own policies. Some publishers will not consider a proposal under review elsewhere, others will. The important thing is to be communicate clearly with whomever you are dealing with. In your query letter, for instance, you might say, "My proposal is currently under review at other presses." In many cases, editors simply sent me an email telling me to try again later. In other cases, they were happy to look at the proposal even if it were under review elsewhere.
Things are very different, however, when it comes to the review process for entire book manuscripts. In my experience, most (but not all) presses will not permit you to have your entire manuscript under review elsewhere while they are reviewing it. There is one exception to this I encountered myself, and which you might ask about. Some publishers will allow you to have your manuscript reviewed at other presses if you confer to them a "right of first-refusal"–which is basically a binding agreement that you will publish the book with them if they accept it, even if another (possibly better) press wants to offer you a contract. The editor at Routledge offered me this, and I was very thankful, since I was able to have my entire manuscript reviewed by multiple places simultaneously (many other presses would not review the manuscript while it was under review with Routledge, but some did!). This sped up the entire book publishing process for me immeasurably. I placed the entire manuscript under review with several presses all at the same time, and a few months later I heard from all three of them at roughly the same time.
Do any other readers have helpful insights or experiences to share?
Yup, I was going to write the same thing