Direct mail has its own language. Below is a handy glossary of the most important terms you’ll come across when planning, buying or measuring direct mail campaigns. Use this as a quick reference — it’ll make briefing a mailing house (and assessing quotes) much easier.
Address validation / PAF
Checking and standardising addresses against Royal Mail’s Postcode Address File (PAF). Proper validation reduces returns and ensures accurate postage.
Append / Enrichment
Adding extra data to records (e.g. demographic, tenure, spending bands) to improve targeting and personalisation.
Batch / Run length
The number of items produced in one print or fulfilment run. Economies of scale often apply — bigger runs usually lower unit cost.
Broken-run / Multi-part pack
A pack containing several items (letter, brochure, flyer, coupon) enclosed together. Used for welcome kits, prospectuses and premium mailings.
Bulk postage / Downstream access
Discounted postage rates achieved by sorting and presenting mail in large quantities or using a downstream access provider rather than paying standard Royal Mail retail rates.
Cleansing / Dedupe / Merge-Purge
Removing duplicates, correcting errors and merging lists so you don’t mail the same person twice. Essential for accuracy and cost control.
Data suppression / MPS
Filtering lists against suppression sources like the Mailing Preference Service (MPS) or internal opt-outs to avoid contacting people who’ve opted out.
DPIA / Data protection
Data Protection Impact Assessment — an audit to identify and mitigate privacy risks. Important for sensitive or large-scale mailings under GDPR.
Envelope teaser (outside copy)
Short line on the outer envelope that teases the message inside and increases open rates (e.g. “Exclusive offer enclosed”).
First class / Tracked / Contracted mail
Postage options that affect delivery speed, reliability and cost. Choose based on urgency and the value of the item.
Inserting / Enclosing / Fulfilment
The physical process of packing items into envelopes, boxes or mailers, and preparing them for postage. Can be machine or hand-finished.
Machine-readable / Non-machinable
Formats that can be processed by postal machines (cheaper) versus irregular shapes or heavy packs that need special handling (costlier).
NCOA / Change of address
Services that update addresses when people have moved — reduces returns and wasted spend.
Offset / Digital / Inkjet printing
Different print technologies. Offset is cost-efficient for medium to large runs with excellent colour; digital is flexible and economical for short runs and heavy personalisation.
PURL / Personalised URL
A unique web address printed for each recipient that links to a personalised landing page — excellent for tracking and conversion.
QR code
A scannable code that connects print to mobile — ideal for quick tracking, sign-ups and rich content.
Segmentation
Dividing an audience into meaningful groups (behavioural, demographic, value) so messaging can be tailored for better response.
Tracking & attribution
Techniques to measure who responded to a mailing (PURLs, QR codes, unique promo codes, dedicated phone numbers) so you can calculate ROI.
Variable Data Printing (VDP)
Printing that allows individualised text and images within the same run — names, offers, images all personalised per recipient.
Waste / Returned mail handling
Processes for logging and dealing with undeliverable items and for updating records to reduce future returns.
Workflow / SLA
The agreed production timetable and service levels (proofing deadlines, delivery windows) between client and supplier.
How Herald Chase can help
If you’d like a one-page PDF of this glossary for your team — or a quick review of any term as it applies to your next campaign — book a free campaign review with our team at www.heraldchase.com. We’ll help translate the jargon into a clear, budgeted plan.
