I am based in south London and have taken casting portraits and headshots for 16 years. I use natural light, indoors and outdoors, rather than studio lighting. Photos are made in Brockley (London SE4), or at a location of your choice in Greater London.
We'll start by discussing what you want from your headshots, and during the session we'll probably make 200 to 300 photos. A typical session lasts between 2 and 3 hours. 
I use digital equipment, so we can review photos at intervals during the session. You are welcome to try different tops, adjust your hair, or shave, for example, if you want to try some different looks. I provide you with an online gallery of photographs in both colour and black-and-white; I can also provide copies of photos on disc for you to keep.
When you are ready, you can select your favourite photos for me to retouch and crop, ready for use: either 6 edited high-resolution photos supplied for digital download or on disc, or 4 edited high-resolution photos printed at 10x8" and supplied for digital download or on disc. I am happy to reformat images to particular dimensions or file-sizes required by Spotlight or other online directories at any time. The total price is £250, or £200 for students.
Additional 10x8" prints from me are £10 each, but I can recommend more economical reproduction companies if you would like to make lots of printed copies.
You are welcome to email me (pete@petelemay.co.uk) or call me (07703 649246) if you have any questions about this service or if you'd like to book a session. 
If you haven't done so already, I recommend that you read the guidelines on photos from Spotlight.