Kids can't remember email address to account

[muddy16]

Long story short my youngest son is using my other sons old account. No one can remember the email address. The only thing we can remember is the account name and his on screen name. Any help on how the hell I get any of this sorted as he's spent loads of money on games which he can't go on. Please help

[Phoenix]

Do you have any kind of proof of purchase for the games on said account? E-Mails/keys/etc?

[Iceira]

Proof of ownership,through its credit card/bank
https://help.steampowered.com/en/faqs/view/40A0-8B4B-B54B-C51A

pretty sure steam have seen such before kids forget the detail all the time.

[Bee🐝]

Recovering Steam Account https://support.steampowered.com/kb_article.php?ref=2347-qdfn-4366

[Joke]

1. Open the steam website in a web browser. https://help.steampowered.com/en/

2. If you show as logged in, please logout.

3. Click the "login" link. (top right of the site)

4. Click the "Forgot your password?" link. (below the login button)

5. Search for your sons current email. He will need one to communicate with steam, so create one if he doesn't have one. Write down the details, and keep in a safe place.

6.Steam will reply that there is no account connected to the email you search for.
However there is now a new button "Search for my account name". Since you know this, fill it in and click the search button.

If you entered the correct account name, you will now see a hint to what the email registered to the account looks like.
Maybe that's enough for your son to remember. If it's not, then click the other option "I no longer have access to this email"

7. Keep following instructions, and eventually you will get the account back again.

[nullable]

And moving forward, manage accounts and recovery codes and all the account details in a proper password manager. It would certainly have saved you from all this hassle.