Nondeliverable

Nondeliverable, sometimes written non-deliverable, is a term used to describe a message, parcel, or instrument that cannot be delivered to the intended recipient under the stated terms. The term appears in several domains, with different meanings but a shared core: failure of delivery under the configured conditions.

In postal and courier services, a mail item may be marked nondeliverable if the address is incomplete or incorrect, the recipient has moved without a forwarding address, the item is refused, or it cannot be transported due to safety, legal, or regulatory reasons. The item is typically returned to the sender or held for pickup; carriers may leave a delivery notice.

In email systems and messaging, nondeliverable refers to messages that cannot be delivered to the recipient, as indicated by a delivery status notification or bounce message. Bounced emails are categorized as hard (permanent failure, e.g., invalid address) or soft (temporary failure, e.g., mailbox full); causes include non-existent domains, blocked recipients, or policy blocks.

In finance, non-deliverable contracts are cash-settled foreign exchange instruments used when one or both currencies are subject to restrictions on delivery. Non-deliverable forwards (NDFs) or similar instruments settle in a freely traded currency, typically USD, based on the difference between the contracted rate and the prevailing spot rate at maturity. They are common in emerging markets and among multinational corporations seeking hedges without physical currency delivery.

Terminology varies; nondeliverable is often hyphenated as non-deliverable, depending on industry and region. See also delivery status notification, bounce message, non-deliverable forward.