What small customer mistakes have caused you the most operational pain?

We’ve been interviewing ecommerce merchants and noticed a theme: small mistakes made by customers often cause outsized problems for the business.

Examples we’ve heard include:

Customers misspelling their own email or address

Using autofill and not noticing something’s wrong

Forgetting unit numbers or entering the wrong postal code

Submitting outdated shipping details

Typing the wrong quantity and immediately contacting support

Most of these aren’t technical bugs. They’re just everyday human errors that can lead to failed deliveries, frustrated buyers, refunds, or even chargebacks.

I’m curious how other teams handle this. Do you rely on post-order reviews? Do you flag risky orders internally? Or have you found tools or flows that reduce these issues before they become problems?

For context, I work with a team that built a small tool for one part of this (address input cleanup), but I’d love to hear what other patterns or fixes people have seen across different kinds of products.