UK testing figures have certainly been compounded "beneficially". Someone gets a nose swab and a throat swab, that's two tests. They need it redoing due to inconclusiveness, that's another two. Confirmation with a blood test could add to that, or if they were negative in the morning but there was still concern they were too early to detect properly the highly suspected result, they might be tested again in the afternoon (assuming the results were available by then!) and that adds up to more tests (maybe still not confirming anything), but still only one person tested.
When, despite all this (and other practices) they still needed to make it look like more tests were done than were (already a small multiple of the number of people tested) they added in all thr testing kits mailed out to people on that day. After all, they'd now done as much as they could to ensure the test took place (they can't be held accountable for the delivery, the person taking the test[1], the person returning test, the lab properly processing that test and the test not turning out to be ambiguous, after everything else) so obviously they count it as a test as soon as it is first sent out..?
Then they stopped working on numbers of tests done (or 'in progress', however hazily) and switched to testing capacity. If they had test kits piling up and lab-time ready to process them but there just wasn't the footfall or not enough people got to the point of mail-ordering their kit, that shouldn't impact upon the potential number of tests done (however imaginatively) as an ever more ambitious target waa stretched for and desperately needed to be seen to be accomplished.
Then they added in tests done to test the tests (or potentially done) and even the new capacity to conduct antibody testing, even though it wasn't the kind of test they were promising this target to accomplish and wasn't even being used yet, just paid for (or invoiced for?) and actually sitting idle waiting for the time they'd eventually usefully switch to "have you had it" over the currently required "have you got it".
*Woooooosh.....* *BOOM BOOM*
Wow, those goalposts have broken the sound barrier, they've been moving so fast.
[1] Apparently some versions asked that a single swab (and just a single end of that swab..) be used to self-sample deeply into the recipients throat and nose. So not sure if that could ever count as "two tests", though I imagine it's possible.