PCR Test - Crossing to South

[AFC]

I had a PCR test on Thursday, and am looking to cross tomorrow, would this PCR test still be valid as it falls within the 7 day deadline, or is a negative test needed 48 to 72 hours before crossing?

[toaodave]

Where did you get the test done and what is the cost? I am looking to come out in the next few weeks, I believe my test in the UK will be good enough to cross into the north as it will be within the 7 days but I will need to get another before travelling back.