---
type: guide
title: "Popular EDDM Postcard Sizes and USPS Mailing Guidelines"
description: "The three most popular EDDM postcard sizes, the USPS size rules every mailer must clear, and how to pick the right size and mail it without a permit."
resource: https://www.4over4.com/guide/popular-eddm-postcard-sizes-and-usps-mailing-guidelines
tags: ["guide"]
timestamp: 2026-07-20T18:54:40.856Z
---

# Popular EDDM Postcard Sizes and USPS Mailing Guidelines

The three most popular EDDM postcard sizes, the USPS size rules every mailer must clear, and how to pick the right size and mail it without a permit.

See [all guide concepts](index.md).

- Page type: guide
- URL: https://www.4over4.com/guide/popular-eddm-postcard-sizes-and-usps-mailing-guidelines