Trying to understand how SIPs work in Coin

I’ve been using COIN SIPs for well over a year now and I’m trying to understand how exactly the SIPs work - especially the order dates.

Say I have a bunch of SIPs for the 26th of every month through NACH mandates and one of them is a AMC SIP. This is what happened for the current month:

  • All the non-AMC SIPs were placed on 24th 02:15 AM
  • The AMC SIP was placed on 26th morning at 06:15 AM

The actual money transfer for all of them happened today morning at around 09:15 AM.

Could someone explain what’s happening? This doesn’t actually affect me in anyway, I’m just trying to understand what’s happening under the hood.

  • Why are the non-AMC SIPs getting placed 2 days prior?
  • Why does the money transfer itself waits until the date I set it up for? (26th)
  • How is the process different for non-AMC SIPs v/s AMC SIPs? (i.e., what is the flow of the money from my account to the Mutual Fund in both the cases)?

Finally - also wanted to know what happens if a NACH mandate fails on the 26th for whatever reason. Will Coin keep trying (which means I’ll keep getting NACH failure charges from my bank)?