Category

Postal Tips

Practical articles and lookup guidance for postal tips.

Postal Tips

How ZIP Codes Help Mail Delivery

A practical guide for using ZIP code data, postal records, and location lookup tools with confidence.

May 18, 2026 Miranda Taylor

Postal Tips

What ZIP+4 Means and When to Use It

A practical guide for using ZIP code data, postal records, and location lookup tools with confidence.

May 17, 2026 Miranda Taylor

Postal Tips

ZIP Code vs Postal Code: What Is the Difference?

Understand how U.S. ZIP codes compare with postal code systems used around the world.

May 12, 2026 Miranda Taylor

Postal context

About U.S. ZIP Codes

ZIP codes are a United States Postal Service system introduced in 1963 to make mail routing more accurate and efficient. The standard format uses five digits, while ZIP+4 adds four more digits for a more precise delivery segment.

ZIP codes cover the United States, its territories, military mail routes, and other USPS delivery points. This directory organizes that data for practical lookup by ZIP code, city, county, and state.