International Letters & Mailings
Sending international mail via the U.S. Postal Service (USPS) requires careful adherence to foreign content restrictions and strict customs regulations. Review the service options, customs thresholds, and addressing policies below to ensure your international mail is compliant.
USPS Service Options and Content Restrictions
When preparing international mail, the contents of your mailing dictate your service eligibility. You must check current USPS Service Alerts to identify active service disruptions or content restrictions in your destination country.
Available service tiers include:
- Expedited Services: Priority Mail Express International and Priority Mail International
- Standard Services: First-Class Mail International
- Business Services: Airmail M-Bags (for large volume printed matter)
To estimate the postage for your mailing, utilize the USPS International Rate Calculator.
International Customs Thresholds
Customs forms are legally mandated for international mailings based on weight and content type. Failure to attach required customs forms will result in the immediate return or seizure of the mail piece.
- Non-Document Items: A customs form is strictly required for any mail piece containing items other than documents, regardless of weight.
- Documents Over 16 Ounces: If an item contains only documents but weighs more than 16 ounces, you must print and attach three copies of the designated USPS customs form.
International Address Formatting
To ensure processing by automated optical character readers, international address labels must be printed clearly and aligned straight.
Recipient Address Format
Recipient Address Guidelines
- Use all capital letters and type or write legibly in English.
- Limit the address block to a maximum of 5 lines.
- Arrange the recipient address using the following structure:
| Line 1 | ADDRESSEE'S FULL NAME |
| Line 2 | STREET ADDRESS or P.O. BOX NUMBER |
| Line 3 | CITY or TOWN |
| Line 4 | PRINCIPAL SUBDIVISION (e.g., province, state, county) and POSTAL CODE* |
| Line 5 | COUNTRY NAME (written in full; do not abbreviate) |
*In certain destination countries, the postal code must precede the city of town. To verify specific country formats, review the USPS International Country Codes and Mapping Guide (PDF).
Return Address Format
Your return address must follow this exact university format. If your item requires a customs form, the return address on the envelope and the customs form must be identical.
| Line 1 | SENDER'S NAME |
| Line 2 | DEPARTMENT NAME [and Phone Number] |
| Line 3 | UC SAN DIEGO |
| Line 4 | 9500 GILMAN DR MC [Mail Code] |
| Line 5 | LA JOLLA CA 92093-[Mail Code] |