If the lease ends, the tenant stays beyond the lease end date, the landlord cash the rent check, then the lease automatically goes into month-to-month.
Month-to-month lease requires the landlord to provide the tenant with written notice (either 30-day or 60-day)
California Tenants Guide: http://www.dca.ca.gov/publications/landlordbook/index.shtml
CA Tenants Moving-Out: http://www.dca.ca.gov/publications/landlordbook/moving-out.shtml
Just a friendly reminder, if you plan to buy a home, then sign a month-to-month lease agreement. This will allow you to move out with a 30-day notice to the landlord. The average real estate transaction is about 45 days so this time line works well with the required notice to your landlord. Don't be entice with one or two year lease for lower rents because homeownership outweighs the benefits of renting.
I hope the information helps.
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