If you provide substantial services that are primarily for your tenant's convenience, such as regular cleaning, changing linen, or maid service, you report your rental income and expenses on Schedule C (Form 1040), Profit or Loss From Business,
If you provided substantial services to your tenants in 2017 you can amend your 2017 tax return to report the services on Schedule C. Each unit is treated separately so for 2018 you report your substantial services on Schedule C when you file your 2018 tax return.
The link below is to Publication 527 and has information,(page 12) that you may find useful.
[Edited 04/07/2019|11:24 am PDT]
https://www.irs.gov/pub/irs-pdf/p527.pdf
