The standard that INZ try to work to is acknowledging the receipt of an SMC application within 3 days of it arriving in the mailroom, but this isn't usually the reality unfortunately, due to huge volumes of applications coming into the mailroom every day and not enough staff resources to process it. For SMC applications I have represented in the past, I have seen the timeframe from when an application was sent to when we received an acknowledgement letter range from 3 days to up to 3 weeks. It's frustrating but an unfortunate reality of a government department trying to manage huge volumes of work on a limited HR budget