The building isn't enough. Mail needs the apartment number too.

Your customer lives in apartment 4B. Your data only knows the building. In a house, that gap wouldn't matter — in a building with two hundred units, it's the difference between delivered and returned.

Why a missing apartment number breaks delivery

Missing or incomplete unit numbers are one of the most common reasons mail comes back undeliverable. The carrier can find the building, but the building isn't the delivery point — the apartment is. Some pieces get returned marked insufficient address. Others land in a mailroom and quietly go nowhere. Either way, you paid for postage and the customer never saw your message.

There's a second cost that's easy to miss: incomplete addresses also break change-of-address matching. NCOALink® needs the full address — apartment number included — to recognize a move. A record without its unit number can't be matched, so when that customer moves, the move slips past unnoticed. That's why apartment append and NCOA processing work so well together: completing the address first means the move gets caught.

How the append actually works

First, DPV® — the USPS delivery-point validation data — identifies which of your addresses point to a multi-unit building but are missing the unit number. Those records are then compared against a national consumer file, and when the name and street address both match exactly, the apartment number comes back. That exact-match standard is deliberate: an apartment number appended to the wrong person is worse than no append at all.

What you get back

Your data returns with the original records intact and the missing apartment and suite numbers filled in wherever a confident match was found. Every record carries a code showing what happened — completed, already complete, or unmatched — so the improvement isn't a black box. You can see exactly what changed, and your master data gets better, not just one mailing.

A person will look at it with you

We've been doing this since 1994, and we still start every project the same way: a real person looks at your data and tells you what it needs. If your addresses come mostly from single-family neighborhoods, apartment append may not be worth your money — and we'll tell you that before you spend it. When it is the right fix, you'll get it back documented, with someone you can call if anything looks off.

How it works

1. 1

   Start with a conversation

   We'll talk through how your addresses were collected and tell you whether apartment append will actually help — and roughly how much of your data it's likely to touch. If it isn't the right fix, we'll say so.

2. 2

   We find the addresses that need a unit

   Records that point to a multi-unit building but are missing the apartment or suite number get identified — these are the addresses where mail is most likely to stall or come back.

3. 3

   We append the missing numbers

   Where a confident match exists, the apartment or suite number is added and the address is standardized so it's ready to mail.

4. 4

   Every change comes back documented

   Your original records stay intact. Each one returns coded, so you can see exactly which addresses were completed and which couldn't be matched.