Import the ZIP column as text. Then check the exact file you hand over. Excel can drop the zero from a ZIP code, and a screen that looks right can hide it.
Reviewed October 17, 2026
Why ZIP codes lose their zeros
Microsoft says Excel automatically removes leading zeros from data like postal codes. Microsoft: leading zeros A ZIP that starts with zero can come out one digit short.
Import the column as text
Microsoft's method: open the Data tab, choose From Text/CSV, then set the column to Text in the query editor. Microsoft: text import Do that for the ZIP column. Do not trust a quick look at the screen.
Fixing it later does not work. Microsoft says setting a column to Text does not change numbers already entered. Microsoft: format limits If a zero is gone, go back to the original account record. Do not guess the missing digit from the length.
Check the file you will send
We suggest this check. Pull several records from the exported file, including ZIP codes that start with zero. Compare each address to its source. Approve that exact file, and keep a separate copy for edits.
The Propane Safety Pro mailing starts with the customer list you supply. Propane Safety Pro: mailing process Ask which file formats it takes before you export. Do not assume a certain spreadsheet import is included.
What if our spreadsheet already lost a zero?
Go back to the source record and get the full ZIP code. Have the person who approves your list fix that row before the file is released.
General information, not legal advice.
Get a Duty to Warn quote and ask which list file formats the mailing takes.
About Bill Stomp
Bill Stomp built Propane Safety Pro. He is a war veteran who ran over 87 propane branch offices across 12 states, and he has helped more than 200 propane companies improve their profits, sales, safety and operations.