Anthropic: You can't change your Claude account email address

Why is this the case? I don't understand, can somebody explain the logic to me here?

Maybe used the email address as a primary key. Ask me how I know.

Well it does eliminate a whole list of problems related to account takeover, account recovery workflows, legal questions regarding which email owns the data, etc. Sometimes less is more. Secure, reliable, simple.

I fail to see how preventing email changes solves the issues you listed, or how allowing it necessarily makes them worse.

That's pretty obvious to anyone who had to maintain a high traffic site. Just the tip of the iceberg (I haven't included additional legal issues and other):

1.1 Strong protection against account takeover

Email change is one of the most abused recovery vectors in account takeover (ATO).

Eliminating email changes removes:

Social-engineering attacks on support

SIM-swap → email-change chains

Phished session → email swap → lockout of real user

Attacker must compromise the original inbox permanently, which is much harder.

1.2 No “high-risk” flows

Email change flows are among the highest-risk product flows:

Dual confirmation emails

Cooldown periods

Rollback windows

Manual reviews

Fixed email removes an entire class of security-critical code paths.

1.3 Fewer recovery attack surfaces No need for:

“I lost access to my email” flows

Identity verification uploads

Support-driven ownership disputes

Every recovery mechanism is an attack surface; removing them reduces risk.

You're very wrong, because account takeover can still happen due to a compromised email account. People can and do permanently lose access to their email account to a third party.