No uk birth certificate

[itsgettingweird]

Does this matter?

So far it's never been an issue but my ds was born abroad and although British with a British passport doesn't have a British birth certificate.

He's 19.

Is there a way of getting one if needed ever?

No. You take the original local certificate and the consulate enters onto the British birth registry.

It is just the same as a birth certificate for someone born in UK.

They are all copies, the same as your marriage certificate or any death certificates you might have are copies. The "original" is the central register.