Hi - I was hoping somebody could help!

I was the tenant in a lease that ended 3/10/09. The lease stated clearly and in BOLD that I was required to give 30 days notice that I was not renewing the lease. I gave only 20 days. The lease provides no direct penalty or remedy for the landlord for me NOT giving 30 days notice. My issue is, the lease then states that if I fail to sign a renewal lease, or to vacate, then I would be subject to month to month rent. Well, I vacated prior to 3/10, on 3/7. So according to the lease I am not a holdover or MTM tenant. So I don't think I owe anything past 3/10. So of course they billed me through 3/20, and I paid through 3/10. Now they have it with a collection agency and it's about to hit my credit. Do I have a case here?

Nope. Be happy they aren't billing you for an extra month. If the lease expired on 3/10 and you didn't give notice prior to 2/8 (remember only 28 days in Feb), then you automatically became a month to month tenant as of 3/11. Theorectically they could have charged you to 4/10. So pay the extra 10 days!

Thanks for the super quick response. So the lease is overruled by some CA law? Why do I automatically become an MTM tenant if the conditions in the lease that would make me an MTM tenant were not met (ie I vacate prior to the lease end date)?

You are looking at this from the wrong angle. You became an MTM tenant for the period starting 3/11 on 2/9 when you failed to file the required 30 day notice of renewal. When you actually vacated is immaterial. When you did give notice (on 2/18?) the landlord applied the 30 day notice rule to your tenancy. Therefore, your tenancy expired on 3/20. So he is charging you (legally) rent to that date.

Again, when you vacate is immaterial, you had the right to occupy the premises until 3/20. Now there is one caveat to this. If the landlord moved another tenant in prior to 3/20, then that would mitigate your responsibility since he can't double dip.