C19 Antigen Test for return from Spain. Have i got this right and what is the catch?

bigfer

Looking to go to Spain next month and was mugging up on the current requirements for returning back to UK. As I understand it, I can purchase an antigen test from C19 to take with me, test myself at the appropriate timeslot and then upload the results to obtain the necessary certification emailed to me within a short time frame, allowing me to board my return flight home. (2 day test to be sent to home address, not really bothered about security of this tbh)

This would then save me the hassle and expense of trying to find a Spanish provider in rural Spain. From trustpilot reviews, it would appear C19 to be a reasonable company to use. 
Is this a correct interpretation of the current rules. I am sure this sort of question has been asked numerous times, but I just fail to see how this provides a secure basis for testing. However, I will abide by the spirit of the rules and just want to find the easiest method to safety board a flight home quickly if Spain suddenly finds its self on the red list.
TIA 

CKhalvashi

I cannot confirm how C19 work, but this would effectively be it.

I have always used private local providers when testing, but tend to be a city dweller.

bluejo101

That's what we did for Majorca. Took the tests with us from Chronomics, did the test, uploaded the result and UK Border force had it all on their system when we arrived. 

bigfer

Did you have to video all the palaver or just send a photo of the negative test?

silvercar

If you are double vaxxed, you don’t need a pre- flight test from 4 October.