A supplier can generate an InCheck Report for a specific calendar month within a 42 day window. The 42 day period starts after the last day of the month the supplier is reporting on, not from the beginning of the month. 

For example, if a supplier wants to generate an InCheck Report for April, the 42 day reporting period begins on 1 May. This means the report can be generated at any time from 1 May to 11 June (42 days after 30 April). 

After the 42 day window has passed, the supplier will no longer be able to generate the report for that month.