How many days notice to give for 12-month tenant rent increase?

[Paul Lee]

Hi guys,

I am closing on a 4-unit multi-family on July 11th with 3 existing tenants with written lease agreements.  All of their leases expire at the end of July.  How many days' notice am I required to give them to let them know that rent is increasing?

I spoke with a property manager that said I am required to give 45 days' notice, while HB21-1121 - Residential Tenancy Procedures says 60 days' notice without a written lease agreement. 

https://leg.colorado.gov/bills...

I am planning to extend a month-to-month lease so the tenants have the option of searching for other units if they don't agree with the price increase.  Thank you in advance.