This information came straight from the source (Costco corporate office at Issaquah, Washington). Thank you
There are people saying that you don't have to cut coupons off Costco coupon book. They say we can just show them your entire coupon book and all items will be discounted automatically. Every single coupon has a same bar-code (UPS code), so it seems more convincing not to cut coupons.
But, you are supposed to cut coupons and give to the cashier. They want the coupons for accounting purposes.
People reported that they didn't have to cut their coupons. They said the price was automatically deducted without handing in the coupon. This happened to me also. This automated mark down is a new system adopted by Costco to ensure best services for the members.
But the bottom line is that they need the coupons.
About the cashiers who didn't take your coupons earlier? Basically, they were confused with the new system and made mistakes. Soon, your cashiers will ask you to cut the coupons.
So, cut the coupons, please.
* Evidently, at corporate office, the name for Costco coupon-book is MVM (Multi Vendor Mailer). I did not know that.