What is the difference between next-day and same-day ACH?

Standard ACH settles in 1-3 business days. Same-day ACH (available since 2016) settles the same business day if submitted before 2:45 PM ET, for a $0.052 per-transaction surcharge. Next-day ACH settles the following business day. For most businesses, standard ACH is fine — same-day is useful for urgent payroll or time-sensitive vendor payments.