---
title: "USCIS Faxing FAQ - Onetime Fax"
description: "How faxing to USCIS works: when fax is accepted, what to include, privacy tips, and troubleshooting."
canonical: "https://www.onetimefax.com/faq/uscis-faxing/"
---

# USCIS Faxing FAQ

What to know before faxing immigration documents.

Related guides: [International faxing](/blog/send-international-faxes) · [Country codes list](/blog/international-fax-country-codes) · [Troubleshooting](/blog/fax-troubleshooting-guide)

Can I fax documents to USCIS?

USCIS generally prefers online uploads (MyUSCIS) or mail. Some workflows may provide a fax number for urgent supporting documents—only use the number and instructions provided for your case.

How do I format a USCIS fax?

Single PDF: cover sheet → case notice/receipt → your documents. Include receipt number, names, DOB, and any A‑Number on the cover. Use clear scans and page numbers.

Is it secure to fax immigration documents?

Use a trusted service with encryption in transit, avoid public Wi‑Fi, and minimize PII on the cover page. Always verify the destination number from official correspondence.

When should I fax USCIS?

Send during business hours for the office handling your case. For time-sensitive RFEs/NOIDs, follow the notice instructions exactly.

My USCIS fax failed. What next?

Confirm the number and identifiers, resend as a clean PDF, and retry within business hours. See [troubleshooting](/blog/fax-troubleshooting-guide).