What does each failed last mile delivery attempt actually cost?

Each failed last mile delivery attempt costs the carrier €1–3 in direct redelivery and operational costs — plus the return-to-depot cost if the parcel cannot be left securely. For a carrier processing 1 million deliveries per month with a 25% first-attempt failure rate, that is 250,000 failed attempts per month generating €250,000–750,000 in direct redelivery costs before any impact on customer satisfaction or repeat order rates. PUDO out-of-home delivery eliminates the first-attempt failure problem entirely by decoupling delivery from the recipient's presence at the address.