Heathrow Airport adds £ 8.90 in tax, applied on all tickets, paid as a "United Kingdom Exceptional Regulatory Charge." The same tax applies on all the departures of Heathrow, regardless of the cabin and the distance. That is basically intended to recover some of the losses associated with coronavirus.
This is in addition to all other taxes on Heathrow fares (some of which are airport specific and some of which extend to all airports in the United Kingdom), including air passenger fee, passenger service charges, etc.
Due to the pandemic, traffic at Heathrow Airport is way down, and this causes the airport to lose revenue. Heathrow Airport has some fixed-cost features and it is the airlines' duty to pay for these expenses. Airlines are faced with a higher bill for these services than normal, and the airport claims that the airlines have asked this tax to be added to ticket prices. In the future, the tax could be adjusted, and the target is to remove it by 31 December 2021.
247london-airport-transfers.co.uk