It is just awful clicking on a site for lighting and after much searching finding out that they don't sell what you are looking for. Here below are a selection of merchants who deal in lightbulbs. You will find lightbulbs on all these sites and therefore will not waste time clicking through to lighting suppliers who only sell table lamps or garden lighting for instance. It is worth taking the time to go through all the sites on this page as they all contain lightbulbs.
24/7 Electrical
Brick lights, downlights, spots, garden, wall, uplighters, low voltage, party string ball lights, lanterns and a large range of outdoor lighting.
Tooled-up
Buy bulbs and accessories, halogen lamps, inspection lighting, outside lights, torches, flashlights and lanterns
Argos
Lightbulbs, flourescent, 12v halogen, 240v halogen, flourescent lamps, low energy lamps, reflector lamps, night sensor bulbs, SON lamps, tungsten halogen lamps.
DIY Tools
At DIY Tools buy torches and flashlights, table and floor lighting garden lighting, lightbulbs, downlights, wall lights, desk lights, garden lights, solar lighting, spotlights.
B&Q
Lightbulbs, candle lightbulbs, energy saving lightbulbs, spotlight, coloured, halogen, striplight, pigmy lightbulbs.
Marks and Spencer
Buy bulbs.
EBulbShop.com
Energy saving lightbulbs
Trueshopping
Floodlights, security lights, worklights, torches, bulbs, halogen lamps, led, flourescent
Partmaster
Bulbs including spotlights, halogen and energy saving plus solar powered garden lighting, security lights, torches and christmas lights
Robert Dyas
Lightbulbs, torches, outside lighting, christmas lights