Every place on this list has plugs and wifi, and they won't make you feel awful if you sit there all day with a laptop.
I discovered about a month ago that in their Soho branch, they have a downstairs area and it changed my life, because honestly the only bad thing I was going to say about it was that it was too small. No no Emma, the upstairs is too small. The coffee is great even if the staff can sometimes seem a bit half arsed, and they don't mind you staying there literally all day, even on a Saturday. Get there early to grab a seat in the window upstairs and watch the world go by. I mean, do your work. Obviously.
My East London favourite. Definitely the lightest of all of the options on this list thanks to its translucent ceiling, and their hot lunches are honestly brilliant - as are the treats.
Joe and the Juice
Okay, so granted I've never had Coffee here. But their juices are so so good I can't even explain. ALSO, tuna and avocado on toast is a cracking option. It can get a bit loud and there aren't accessible plugs near to every single seat in every single branch.
These guys have a couple of locations around the back streets of London Town, but Wardour Street is my personal favourite for getting stuff done.
My only gripe with this is that the seats aren't the comfiest, but the vibe is motivating (yeah I just went there) and their sandwiches are something else.
Fleet Street Press
On the east side of central, kind of somewhere between Temple and Blackfriars. Wonderful tea, wonderful food, little bit on the small side but also beautiful location just opposite the royal courts.
This is my current absolute favourite. There are loads of super healthy and vegetarian snacks as well as the TASTIEST lunch boxes that you can make up. It's a bit pricey, but I love it as a treat - and coffee + muffin = £3.50 which really isn't any more than anywhere else.
They have sparkling water on tap. For real. And if you like sparkling water, you'll really really appreciate that. They also do their bit to be a little bit more eco friendly without preaching at you every 4 seconds which is brilliant.
One of my personal favourites because it's underneath a theatre. Plugs not quite so plentiful but definitely available. Food delicious, if a little pricey again.
Seven Dials, not soho, kids. Don't make that mistake like I did, for real. Soho is BUSY AND LOUD and even noise cancelling headphones didn't help the situation. For Seven dials, you gotta get there early, but once you do and you've installed yourself, you're safe for the day. Cracking wifi, cracking people watching spot, space, variety of proper seats and sofa kind of seats, upstairs and downstairs seating, many good things. I guess it does get loud sometimes, but not unmanageably so.
Fleet River Bakery
Near Holborn station, just down Kingsway a bit. It's very bakery-esque in the food that they serve so don't expect any kind of healthy salads, and it can sometimes feel like you're in an underground pit because of the lack of windows (and to be fair, it is underground), but still a good go-to. There's a good mixture of spaces for doing either individual or group work, too.