@mikeyboy Just to clarify what I said WAS NOT incorrect advice. Maybe it is different depending on the Day 2 Test provider as
@feedthegoat27 has pointed out but what I quoted was partly advice from City and my own experience. Only trying to help as we all are.
City's advice is "Booking receipt of your Day 2 private PCR test". which for me = email confirmation or invoice
My onw booking email confirmation included the reference code needed for the UK Locator. I expected any confirmation would include this code as when I registered my test kit it asked me for this code. Maybe it is different for other providers (I used Dante Labs). After I registered it just said "complete" and did not give me anything further, no further code or ref and no confirmation email that I registered. Hence why I said no need to regasiter . Apologies if your or anyomne else's test provider is different but as long as you have the code you are ok.