Cost of living in london

How much monthly income (after housing, bills, transport and taxes), do you need to live in london?

Extremely broad question impossible to answer with more context. Are we talking a single room in a house share in Zone 5, or a luxury penthouse in Kensington? Transport will obviously be much more expensive if you choose to live further out, but there are affordable options (its definitely possible for people with average levels of fitness to commute in by bike for example). Taxes again will be very dependent on your circumstances; you don't have to pay council tax if you're a student, you get a 25% discount if you're required to pay it but you live alone, and if you live with other people you can split the cost. The amount will depend on the specific council and the size of the property. If you privately rent a room rather than a whole property (i.e. in a HMO) then council tax is normally included in the rent.

For a very rough ballpark figure, I paid £175/week to live in Tottenham in 2016 (student halls, en-suite room, all inclusive of bills) and £125/week to live in Harringay in a 2017 (privately rented HMO with five other people, paid water, electric, gas and Internet extra). No doubt prices have increased significantly since then. Regarding travel, monthly/annual travel cards will almost always be a cheaper option, you can look at the prices of these on the TfL website.

If you're trying to figure out if you can afford to move, you're better off creating a budget and working backwards. Use Zoopla/Rightmove to get an idea of how much rent is in the area you wish to live.