Important changes to the UK entry regulations
The UK has approved two important changes to the country's entry regulations. The mandatory Electronic Travel Authorisation (ETA) will increase from £10 to £16 from 2 April, but will not be required for transfers at London Heathrow and Manchester airport.

In September 2024, the UK government announced the introduction of an Electronic Travel Authorisation (ETA) for those crossing the UK border. This is a special permit that can be obtained electronically via a government website or mobile app. The ETA was to cost £10 and allow entry into the UK for a period of 2 years or until the expiry date of the passport (if less than 2 years). Only citizens of the United Kingdom and Ireland and people with a visa, work or study permit for the United Kingdom are exempt from the requirement to obtain an ETA. However, there have been some changes to the system in recent weeks.
The Electronic Travel Authorisation (ETA) has become more expensive: from 10 to 16 pounds. The second change is that the British government has officially confirmed that the ETA will not be needed when transferring at Manchester Airport and London Heathrow.
Source: homeofficemedia.blog.gov.uk