How to delete my account?

If you are a customer, your account cannot be completely deleted as they are all tied together.

That's unfortunate. Is it at least possible to remove the forum part of the account? Since if I want to post I'll do it in the Steam forum in future. And I hate keeping dead accounts alive.

Your customer/forum login is the same, as Island Dog mentioned.  If one is 'deleted' both are.

The only option would be to ban your access to these forums which is more readily achieved simply by your not logging into them.

The advantage of a username remaining 'registered' is that no-one else can adopt your identity by coincidence [or by design] and thus cause confusion to others.

If you wish to remain off these forums either simply do so...or PM myself or Island Dog and your access can be removed for you...;)

Thanks, I think I leave it at that, I don't want to over-complicate things. One of my other forum accounts got hacked, and since I was using the same password for other forums I had to go on a cleaning run. I therefore took the opportunity to delete some my 367574865 forum accounts I created centuries ago and rarely post in anymore. But well, with the upcoming GalCiv III I might get active in the forum again, even if I prefer to post in the Steam forums nowadays since I only need one account to rule them all.

For each account you have, you should have a unique, strong password...

I know! But since I want to keep my sanity, I'm using LastPass now to manage my countless online passwords.

^ You chose wisely.