Travelling: Does your child need a PCR test if they are turning 12 a couple of days after flying

[Phial]

I've asked this elsewhere on the site about a specific country, but I think it would apply to any EU country. I've not got a definitive answer.
We are travelling (to see family) a few days before DS birthday but he will turn 12 while we are away. Does he need a PCR test if the rule is "no PCR test for under 12s". Could anyone point to an official source saying either way? Thanks.

Just get a PCR test, surely?

Cost is £120, plus the uncertainty that it won't be back in time.

Oh I see! Sorry, I thought they were free. I think you'd be expected to treat him as the age is is. He'll be 12 on return, so should be treated as a 12 yo.

I would assume not until his birthday but it may be better to test them anyway before as otherwise you could be trapped abroad for 14 days if he tests positive over there. Think the PCR can pick it up for 90 days and its rife in schools atm.

I've booked him a test. I obv don't want him to travel with covid. There will however be thousands of under 12s untested travelling who may or may not have covid.
I was just wondering if anyone knew the actual rules.