Fixed Term Lease Question

Hello,

Location: California

My lease is a 12-month fixed-term lease from October 1, 2025 through September 30, 2026.

Section 2 of the lease says:
“The term of this Agreement is for 12 months, beginning on October 1st 2025 and ending on September 30th 2026. At which time this lease shall terminate without further notice.”

However, under the security deposit section, there is another sentence that says:
“The Tenant MUST give 30 days’ written notice to vacate premises. If the Tenant fails to do so the tenant forfeits his/her deposit.”

I gave the landlord written notice on September 15 that we are moving out September 25. We are not trying to avoid rent through September 30 and understand that the lease runs through that date.

The landlord texted me saying that because I gave notice on September 15, I now have to move out by October 15, 2026, and that if I move out earlier I will forfeit my security deposit.
I’m confused because the lease specifically says the fixed term ends September 30 “without further notice.”

My questions are:

Can the landlord require me to extend the tenancy/pay through October 15 because I didn’t give 30 days’ notice before the fixed-term lease ended?

Can they legally keep my entire security deposit just because I move out before October 15?

Does the “without further notice” language conflict with the separate 30-day notice clause?

Should I still turn in the keys on September 25, or wait until September 30?