Originally Posted by
gongtiger
I specifically asked the testing place to add all the necessary information on my report (including passport number!).
That's a start.
When you get the certificate, double check that the sample collection method is an *exact match* for one of the MHLW's specified methods.
Ditto for the testing method.
https://www.mhlw.go.jp/stf/covid-19/....html#h2_free5
Perhaps things are a little less pedantic than they were a year or more ago, but folks were turned back at the border because their documentation left agents less than fully convinced that the test had been conducted according to a specified method of sampling or testing.