I certainly don't want to mislead the OP or do anything to reduce their chances, but if their novel really does need to be in the 140,000 range then it would be a great pity for them to damage it unnecessarily. 200,000 like my own
is, I think, unusual - but 150,000 not so much.
There is a lot more flexibility in the UK than is sometimes supposed. Back in 2007/8 when I was on the hunt for an agent several of the submissions guidelines included rigid word limits (eg Greene and Heaton's was 75,000 - 150,000) but these have now largely disappeared, partly due to the recent success of longer books in the fields of fantasy, sci-fi and historical.
Some new small publishers (eg Bridge House) may well keep to limits of 110,000 to reduce their risk element, but these are not necessarily typical. Even competitions for debut novels in the UK right now don't limit below 150,000, eg Pan MacMillan New Writing (50,000 to 150,000), Daily Mail First Novel (80,000 to 150,000).
The best advice I've found on the subject for new writers is this from the
Writers Workshop, which places writers with agents for a living:
A novel of average length is anywhere between 75 – 100,000 words. A novel of 120,000 words is perfectly normal too.
Any book in the range of 150-180,000 words is a long one, and needs to work hard to justify its length. Anything over 180,000 words is really testing the patience of agents and may well make it harder to place. Anything over 200,000 words is almost certainly suicidally long.
The key here is the ability to 'justify its length' - ie the book really has to need every one of those surplus words to go over 150,000 - but even here, the cut-off is 150,000, not 110,000.
Since the OP's novel is 143,000, the difference between these two limits could be crucial. Again, my advice for the UK would be first to make sure the book is as short as it can possibly be without doing it damage. Then check submissions guidelines for any specific word restrictions that would rule you out, and where there aren't any - go ahead and submit.
In the US it sounds a very different story, so this discussion may be purely academic anyway. However, I thought it worth getting this information out there for the sake of any UK-based writers who might be reading.
Louise