In Russia, Kazakhstan and Belarus
Russia
Under Rules No. 354, readings are usually accepted from the 23rd to the 25th, unless the contract sets other dates. You can submit them in the supplier's online account, on Gosuslugi, in GIS ZhKKh or by phone. Without readings, charges are based on average use for 3 months, then by the standard.
Kazakhstan
In Kazakhstan, readings are submitted to the supplier or the city billing centre — via an app, website or eGov; the deadlines are stated on the bill notice.
Belarus
In Belarus, water and electricity meter readings are usually submitted to the housing and utilities organisation or the electricity supplier via a website, «Raschet» (ERIP) or by phone.
Sources: Rules for the provision of utility services (Government Resolution No. 354, «Правила предоставления коммунальных услуг») — ConsultantPlus, State Housing and Utilities Information System (ГИС ЖКХ, GIS ZhKKh)