Which of these items typically cannot be returned once activated?

Gift cards typically cannot be returned once activated due to their nature as a pre-paid financial instrument. Once a gift card is purchased and activated, the amount is instantly available for use. This creates a challenge in returning them because the funds have already been assigned. Retailers often have policies in place to discourage returns of activated gift cards to prevent fraud and financial loss.

In contrast, replacement parts, service subscriptions, and merchandise coupons may have specific return policies in place, depending on the retailer. For example, replacement parts might be returnable if they are unused and in their original condition, service subscriptions can often be canceled or refunded within certain time frames, and merchandise coupons may still hold a value for exchanges or store credit under specific circumstances. This distinction highlights the unique characteristics of gift cards compared to other items in the list.