Mandatory negative test when traveling to England

From 04:00 (GMT) on 18/01/2021, all persons intending to travel to England will be required to submit a negative test for 
Covid-19, taken no more than 72 hours before arrival in one of the countries. . Even if they have a negative test, citizens 
will still have to isolate themselves for 10 days, unless they come from a country in the so-called "Travel corridors" 
(Bulgaria does not fall into them).
The requirement for travelers to the United Kingdom to fill in an electronic form in advance, in which to provide their 
contact details, travel plan and address at which they will spend the 10-day quarantine.
The requirement to submit a negative test for COVID-19 will apply to those arriving in England by any mode of transport. 
Failure to comply with the new travel test requirements may result in an administrative penalty of GBP 500. 
In the absence of a negative test, carriers may refuse access to the vehicle.