Hi Rukma,
You are right that statutory submission and payment service in part of scope.
Currently, client cannot provide cheque to HMC before deadline (-2 days) they finished in last minute and cannot inform time to collect it.
Thus, they (HR-Chutima) volunteer to pay by theyself just for the tax but social the deadline can be extended from 15th to 29th without penalty then HMC collect cheque on 16th and pay on 17th.
I’m not sure whether client require HMC to stand by at Groupon office and collect the tax’s cheque on 7th to submit on the same day.
If they can improve the cheque processing ealier 2 days before each deadline then no issue.