Is rent through an agency negotiable?

Is it considered OK in the UK to negotiate the price of rent before signing the agreement?

I think I might have agreed to a flat share that is a bit too high. Is £750pcm close to Finchley Road tube a bit too high? I do love the location as it is across the street from a large Sainsbury's and Vue cinema, and lots of other shops nearby. And it is in between Finchley Road tube (to my workplace and to central London) and the overground (one stop to Hampstead Heath and few stops to Camden town with direct link to Shoreditch/Hoxton).

The bedroom is twice the size of my previous room in willesden green, which I paid £600pcm for. Although I still feel that £750 for a room is still a bit steep. While the location is good IMHO, it's no Shoreditch where that kind of rent is expected.

Have you signed a contract already?

DH and I have been in this flat for a few years (and he was here a few years before that) and our landlords have increased our rent twice. Both times we've been able to negotiate to a smaller increase.

Having said that, my experience may be different as we're already in the flat. Keep in mind that flats go quickly in London and if you don't want to pay £750, the landlord/letting agency will easily be able to find someone who will.

My thought: don't underestimate the ease of having a large shop nearby. It makes life soooooo much easier. But, of course, don't break your budget because of it.

Yeah, I already did sign the contract already right after I viewed the place. There were 3 others viewing the property with me, and when another person showed interest in renting, I jumped in without negotiating. It's just across the street from a large Sainsbury's (size comparable to big supermarkets in US/Canada, which is unheard of in Inner London) and two blocks away from Waitrose.  And within less than 5 min walk are two stations: the underground direct to the West End, South Bank, Canary Wharf and the overground direct to Hampstead Heath, Camden Town, and East End (Shoreditch/Hoxton/Dalston).

Yeah, I already did sign the contract already right after I viewed the place.

If you've already signed a contract, I doubt there's any chance for negotiation.