Do bank certificates need to be notarized for Thai visa applications?

Nope

I'm Swedish, applied in Hong Kong and my documents were just downloaded PDFs from my Swedish bank app in English.

No

No

Most bank apps now have an option to digitally certify the pdf whether that carries any more weight I’ve no idea

Good to get an offical stamp from the bank. But given they often need updated financials I just supplied bank pdfs

No, you do not need your documents notarized. They would have stated that in the application process

I keep seeing questions like this, I'm wondering whether that only happens if you apply outside of your country of citizenship...

I'd have thought applying from the country one is a citizen of would mean that the embassy would know and understand the local banks, therefore not requiring that...

Am I totally off the ball park

No. Finland, just the pdf from bank app

Depends on which embassy you're applying through, and whether the certificate is from a Thai bank or a foreign one. Requirements aren't standardized across embassies, if you're applying with foreign bank documents, some embassies want them translated and certified/notarized by a government agency in that country before they'll accept them. Worth checking the specific requirement for the embassy you're using before you submit.

We handle notarization and document certification for DTV applications if that's ever useful, feel free to DM us.