# 39 CFR § 310.4: Responsibility of carriers

> Federal · Regulations · In force

URL: https://www.frixlaw.com/law-library/statutes/ecfr-39-310.4

## Section

- **Citation:** 39 CFR § 310.4
- **Heading:** Responsibility of carriers
- **Jurisdiction:** Federal
- **Kind:** Regulations
- **Status:** In force
- **Text as of:** September 22, 2026
- **Source:** Publisher's official text
- **Location:** Title 39—Postal Service > CHAPTER I—UNITED STATES POSTAL SERVICE > SUBCHAPTER E—RESTRICTIONS ON PRIVATE CARRIAGE OF LETTERS > PART 310—ENFORCEMENT OF THE PRIVATE EXPRESS STATUTES

## Text

Private carriers are cautioned to make sure that their carriage of matter is lawful within the definition, exceptions, suspension, and conditions contained in this part and in part 320 of this chapter. They should take reasonable measures to inform their customers of the contents of these regulations so that only proper matter is tendered to them for carriage. Carriers should desist from carrying any matter when the form of shipment, identity of sender or recipient, or any other information reasonably accessible to them indicates that matter tendered to them for carriage is not proper under these regulations.

## Nearby sections

- [39 CFR § 310.1 § 310.1 Definitions.](https://www.frixlaw.com/law-library/statutes/ecfr-39-310.1.md)
- [39 CFR § 310.2 § 310.2 Unlawful carriage of letters.](https://www.frixlaw.com/law-library/statutes/ecfr-39-310.2.md)
- [39 CFR § 310.3 § 310.3 Exceptions.](https://www.frixlaw.com/law-library/statutes/ecfr-39-310.3.md)
- [39 CFR § 310.4 § 310.4 Responsibility of carriers.](https://www.frixlaw.com/law-library/statutes/ecfr-39-310.4.md)
- [39 CFR § 310.5 § 310.5 Payment of postage on violation.](https://www.frixlaw.com/law-library/statutes/ecfr-39-310.5.md)
- [39 CFR § 310.6 § 310.6 Advisory opinions.](https://www.frixlaw.com/law-library/statutes/ecfr-39-310.6.md)
- [39 CFR § 310.7 § 310.7 Amendment of regulations.](https://www.frixlaw.com/law-library/statutes/ecfr-39-310.7.md)
- [39 CFR § 320.1 § 320.1 Definitions.](https://www.frixlaw.com/law-library/statutes/ecfr-39-320.1.md)
- [39 CFR § 320.2 § 320.2 Suspension for certain data processing materials.](https://www.frixlaw.com/law-library/statutes/ecfr-39-320.2.md)
- [39 CFR § 320.3 § 320.3 Operations under suspension for certain data processing materials.](https://www.frixlaw.com/law-library/statutes/ecfr-39-320.3.md)
- [39 CFR § 320.4 § 320.4 Suspension for certain letters of college and university organizations.](https://www.frixlaw.com/law-library/statutes/ecfr-39-320.4.md)
- [39 CFR § 320.5 § 320.5 Suspension for certain international-ocean carrier-related documents.](https://www.frixlaw.com/law-library/statutes/ecfr-39-320.5.md)
- [39 CFR § 320.6 § 320.6 Suspension for extremely urgent letters.](https://www.frixlaw.com/law-library/statutes/ecfr-39-320.6.md)
- [39 CFR § 320.7 § 320.7 Suspension for advertisements accompanying parcels or periodicals.](https://www.frixlaw.com/law-library/statutes/ecfr-39-320.7.md)

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Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/ecfr-39-310.4. Check the current official text before relying on it. Not legal advice.