With regards to the question of simultaneous submissions, I fear I may not be able to offer a set answer. As a publisher, I am not enamored by the thought of an author sending me a manuscript that is currently floating among several other slush piles. However, as an author, I am tempted to cast a wide net for my book and hope somebody bites. The thought of waiting for one publisher to pass on a book before sending it to another editor can be daunting for authors, particularly if a favored publisher takes a year to decide.
I have read stories of books that were rejected by one publisher years after they had been accepted and published elsewhere. It is funny to read, yes, but when one looks at simulataneous submissions from two different perspectives - as I have the ability to do - one will know that there may be serious repercussions to violating the wishes of a publisher or editor. As with any aspect of the publishing industry, there are pros and cons to sending out a book to several publishers at once, and there are things authors must know about publishers before they submit.
In addition to producing quality fiction and non-fiction in eBook, trade and/or hardcover format, a book publisher is ultimately in the business of selling books and making money. In order to stay in business, the publisher must be judicious in selecting which manuscripts are to be included in their catalogs. Depending on one's budget, a publisher may offer anywhere from five titles a year to five titles a week. Consequently, the rate at which a publisher reads through and evaluates manuscripts may vary according to their publication schedule. Normally a publisher will advertise in its submission guidelines how long an author should wait for an answer, yet there are always circumstances that may arise and force delays.
As an author, I can relate with others who want answers now, so that they may either prepare for publication or ready the manuscript to send to another prospect. I have also learned, too, that impatience can backfire on an author. Once, given the choice between submitting a story as part of an anthology or submitting it solo to another publisher, I chose the latter because I wanted to see the story published. Long story short, the latter publisher folded, and the anthology was accepted and published without my story. My work remains unpublished. Sometimes it pays to be patient.
It is acceptable with most publishers to send a query after a sufficient amount of time has passed. If, for example, a publisher advertises turn-around within 120 days, a message after that time period may alert you to the status of your manuscript. As to whether or not it is acceptable to submit to several publishers at once, here are a few things to consider:
1) If a publisher specifies that no simultaneous submissions are allowed, take that into consideration. Reading a manuscript for potential publication is an investment of time and, in some cases, money. Some publishers use volunteer readers for evaluation, some take on the job themselves, while others hire on readers to separate the wheat from the chaff. As such, some publishers may wish to preserve that investment with the knowledge that they have exclusive readership to a work they may wish to contract.
Having said this, an author may be tempted to submit elsewhere anyway, if only to hedge his/her bets. If one publisher passes while another accepts, no harm is done. However, if there is a possibility that two publishers want the work, and both publishers had asked for exclusive reads, there presents some problem. While this dilemma can be remedied by simply turning away the contract by Publisher A without explanation, you will run the risk of being found out when your book is released with Publisher B. Some publishers have long memories, and Publisher A may not be so accommodating should you submit something else to them.
2) If you make a simultaneous submission, alert the publisher. If a publisher does allow simultaneous submissions, an author should be courteous to let it be known if a manuscript is sent to more than one publisher. There may be a possibility a publisher will expedite your manuscript for review if there is the possibility another will claim it. If you are a quality writer with a track record for good sales, you may be placed in the enviable position of having some negotiation power.
3) If you accept a contract for a book still out with other publishers, notify the other publishers immediately! The last thing a publisher wants to do is waste time. One major aspect of the book business is production. Especially with the romance industry, books are released at a steady rate, and publisher does not want to invest time in reviewing a manuscript that is not attainable. This can work against an author who wishes to submit to a publisher at a later date (remember what I said about publishers having long memories).
Think carefully before considering simultaneous submissions. Weigh the consequences and be prepared for every scenario. Keep track of every publisher who has the manuscript and follow-up accordingly when deadlines have passed and when offers are made. As you heed the instructions of each publisher you contact, chances are you will make an impression regardless of whether or not you are contracted. This can bode well for your writing career in the future.
Writing 
