Requiring the tenant to pay additional costs at year end is not a reasonable arrangement. There are often problems related to collecting the difference later on. Your rental agreement would have to be specific and describe what is considered additional costs.

As of September 1, 2021, landlords can file an application for failure to pay utility costs with the LTB. For more information on the September 1 amendments to the Residential Tenancies Act visit https://tribunalsontario.ca/ltb/operational-updates/#sept1.