IN POST key terms

The most common mail class for letters, postcards, and small envelopes; includes ordinary correspondence and bills, receives priority handling, and must be sealed against inspection unless sent at a flat rate.

A category that determines the handling speed, eligibility rules, and price structure applied to a mailpiece, such as First-Class Mail, Periodicals, or Marketing Mail.

A mail class available to authorized publishers and news organizations for distributing newspapers, magazines, and similar serial publications to subscribers and requesters at reduced rates.

A reduced-rate class for bulk advertising, circulars, catalogs, and promotional material mailed in qualifying quantities; formerly known as Standard Mail and subject to preparation and volume requirements.

Sending large volumes of identical or similar mailpieces under a permit, with presorted addresses and documentation, in exchange for lower per-piece postage than single-piece rates.

The process of arranging mailpieces by ZIP Code, carrier route, or delivery sequence before mailing so the pieces can bypass some sorting steps and earn discounted postage rates.

A five-digit numeric code that identifies a geographic delivery area; the first digit represents a region, and additional digits narrow the area to a sectional center, city, or delivery segment.

An extended ZIP Code with four extra digits that identify a specific delivery segment such as a city block, building, or apartment group, improving sorting accuracy and reducing misdelivery.

The exact location where a mailpiece is delivered, such as a mailbox, apartment slot, or business mailroom, identified in address data by a specific delivery point code.

The fee paid to send a mailpiece, calculated from factors including weight, size, shape, destination, and mail class; it may be paid with stamps, meters, or permit accounts.

A pricing tier within a mail class based on weight, shape, and preparation, such as a letter rate versus a flat or parcel rate, or a single-piece versus bulk rate.

Mail bearing postage printed by an approved postage meter or PC postage system, which records the amount paid and is subject to periodic inspection and account billing.

An authorization that lets a mailer pay postage through a prepaid account and print an indicia instead of using stamps, typically required for bulk mailings and business reply mail.

A service that lets a customer return a response using an envelope or card supplied by the mailer, with postage charged to the mailer's permit account only for pieces actually returned.

A service providing proof of mailing and a record of delivery, with a signature obtained at delivery; it does not include insurance and can be combined with return receipt service.

An optional service that provides the sender with evidence of delivery, historically a signed postcard but now often electronic, showing who signed for a tracked or certified item.

A high-security service for valuable items that are logged at each handling point, sealed and secured in transit, and insured up to a declared value for an additional fee.

An amount charged to the recipient when a mailpiece arrives with insufficient or unpaid postage, collected at delivery or at the retail counter before the item is released.

A unique identifier assigned to a shipped item that lets the sender or recipient look up its current status and delivery confirmation through an online or telephone system.

A service that records when an item was delivered and provides the sender with delivery information, often included automatically with certain parcel and expedited services.

A request filed by a customer to forward mail from an old address to a new one for a set period; it requires identity verification and applies to specific names and dates.

The redirection of mail from a customer's previous address to a new address for a limited period after a valid change-of-address order is processed.

A service that keeps a customer's mail at the local delivery unit for a requested date range, after which it is delivered or returned according to the customer's instructions.

A service that supplies a mailer with updated address information for undeliverable or forwarded pieces, usually for a fee, helping the mailer maintain accurate mailing lists.

Mail that cannot be delivered as addressed because of an incomplete, incorrect, or nonexistent address, or because the recipient has moved without leaving forwarding instructions.

Mail that is undeliverable and cannot be returned to the sender, which is opened under controlled procedures to identify the sender or recipient and then handled accordingly.

The legal and ethical principle that mail contents and customer information are protected from unauthorized opening, disclosure, or use, binding postal employees in all handling and retail activities.

First-Class Mail and certain other classes that are closed against inspection, meaning employees may not open it except under specific legal authority such as a search warrant.

A service requiring the carrier to deliver an item only to the named addressee or an authorized agent, with signature obtained and no alternate delivery permitted.

Substances such as flammables, corrosives, batteries, or aerosols that are regulated for mailing and may be accepted only when packaging, labeling, and quantity rules are met.

A document that describes a hazardous substance's properties, health risks, and safe handling procedures, kept accessible where such materials are stored or used.

Gear such as gloves, safety glasses, hearing protection, or high-visibility vests worn to reduce injury risk during sorting, machine operation, or handling of hazardous items.

A safety procedure that isolates energy sources and applies locks and warning tags before equipment is serviced, preventing accidental startup or release of stored energy.

A documented set of procedures describing evacuation routes, alarm signals, assembly points, and assigned responsibilities so employees can respond safely to fire, weather, or other emergencies.

A designated path from a work area to a safe assembly point, marked with signs and kept clear of obstacles so occupants can leave quickly during an emergency.

A written record of an accident, injury, near miss, or security event that captures facts, witnesses, and corrective actions and is submitted through the required reporting chain.

The process of separating mail by destination, class, or delivery sequence so it can be routed to the correct carrier route, facility, or transportation network.

A defined path of addresses served by one letter carrier, used as a sorting destination and as a basis for route-level presort discounts and delivery preparation.

The order in which addresses appear along a carrier's route, allowing carriers to deliver mail in one pass without backtracking and enabling sequence-based mail preparation discounts.

The set of operations that move mail through a facility, including culling, facing, canceling, sorting, and containerization, before it is dispatched to carriers or another facility.

Arranging mailpieces so that addresses and postage are oriented the same way, allowing automated equipment to read and process them efficiently.

A mark applied over a stamp or indicia to prevent reuse and to record the date and place of mailing, often applied by machine during processing.

A sale or service exchange at a counter, such as selling postage, accepting a parcel, or processing a money order, which must be recorded accurately in the point-of-sale system.

The secure compartment that holds currency and coin for counter transactions, counted and balanced against recorded sales at the start and end of each shift.

A prepaid payment instrument sold at the counter for a fee, redeemable for its face amount, and requiring careful identity and record checks to limit fraud.

The funds and related paperwork submitted from a retail unit to the accounting office, reconciled against sales records to verify that receipts match deposits.

The professional assistance given to customers, including answering questions, resolving complaints, explaining options, and maintaining courteous, accurate, and timely interaction.

A communication technique of focusing fully on a speaker, confirming understanding through paraphrase, and asking clarifying questions so the customer's real need is identified.

Techniques for calming an upset customer or tense situation through a calm tone, empathy, clear options, and boundary setting, reducing the risk of conflict or safety incidents.

The practice of entering, checking, and filing information without errors, including verifying names, addresses, amounts, and dates before completing a transaction or record.

The policy governing how long different documents and transaction records must be kept, where they are stored, and how they are securely destroyed when no longer required.