You must pay tax on any profit from renting out property. For California, rental income and losses are always considered a passive activity.Under LAMC Section 21.43, renting dwelling units is a business activity and is subject to a City of Los Angeles business tax. Tomonth agreement is a 30day contract. Each time you pay rent, you renew the contract for another 30 days. You Can Easily File Your Return Online. Filing your return online is an easy and efficient method of filing your sales and use tax return. Rent Registry is an online service portal where owners of rental properties located in unincorporated Los Angeles County can register rental properties. The RSO applies to rental properties that were first built on or before October 1, 1978, as well as replacement units under LAMC Section 151.28. Your rental agreement can be verbal, written, implied, or a combination of them.