Want to know, does congestion charge apply today ? check it out guys! ;) normally you have to pay congestion charge if you pass some area from Monday to Friday at 07.00-18.00 ! but for public holiday, weekend, Christmas eve or even good Friday are free to charge! if you want to pay less, and get discount you can use autopay( CC or debit card charge yearly)! and also if you registered for resident(local) you'll get 90% discount! I.e £1.05 rather than £11.50
for more detail or if you want to register visit this page (https://tfl.gov.uk/modes/driving/congestion-charge/auto-pay) to get discount or using autopay it will need some document to register via online! for resident it can help big time! but if you just passing by, I think paying £11.50 are the most reasonable! at least you only pass Congestion Charge just for once a while! by the way, if you not using autopay, you should pay before midnight otherwise you'll get penalty(PCN)
The best way if you don't want to pay Congestion Charge you must find alternative routes! but it will be hard if you not familiar or maybe you have urgent need!