[denzil]

From what I read in EU the pay is considered personal information and is thus is protected by GDPR. If your employer wanted to share it with 3rd party for something like this, he would need your explicit approval for it.

[Simon_O_Rourke]

Exactly this, plus you'd have the right at any time to inspect your own data, or withdraw permissions at any time.

[shellfishgene]

I think in Sweden all tax returns are public.