STEM OPT Mailing Address USCIS Lockbox — Where to File

Where STEM OPT Applications Actually Go

Let's be direct: STEM OPT extension applications do not file at USCIS field offices, Application Support Centers, or the campus service center nearest you. They file at a centralized lockbox facility in Dallas, Texas. The lockbox address you use depends on one variable only — the state where you currently reside. If you send your Form I-765 to the wrong address or attempt to file it in person at a local USCIS office, it will be rejected and returned to you, burning days or weeks from your filing window.

USCIS maintains separate lockbox addresses for applicants using regular mail versus commercial courier services (FedEx, UPS, DHL). The distinction matters: a commercial carrier cannot deliver to a P.O. Box, and the Postal Service will not deliver to the street address designated for couriers. Using the wrong address type for your shipping method results in delayed delivery at best and complete non-delivery at worst. Both scenarios count against your filing deadline.

The Current USCIS Lockbox Addresses for STEM OPT

As of 2026, Form I-765 STEM OPT extension applications file to one of two Dallas lockbox facilities. The choice depends on your shipping method and your state of residence.

For U.S. Postal Service delivery (USPS Priority Mail, First-Class Mail, Certified Mail):

USCIS
Attn: I-765 C03A
P.O. Box 660867
Dallas, TX 75266

For commercial courier delivery (FedEx, UPS, DHL):

USCIS
Attn: I-765 C03A (Box 660867)
2501 S. State Hwy 121 Business
Suite 400
Lewisville, TX 75067

The "C03A" designation on the attention line refers to the eligibility category code for F-1 students applying for STEM OPT extensions. Including this code ensures your package routes to the correct processing queue within the lockbox.

These addresses apply to all 50 states, U.S. territories, and the District of Columbia for STEM OPT extension filings. USCIS does not maintain region-specific lockbox addresses for this application type. The only variable is the shipping method — USPS versus commercial courier.

Address verification: Before you mail your application, verify the current lockbox address on the official Form I-765 instructions at uscis.gov/i-765. Lockbox addresses change when USCIS updates its contract with lockbox vendors, and outdated addresses from prior years will cause delivery failures. The instructions page lists the official addresses alongside the form version currently accepted.

What the Lockbox Does — And What It Does Not Do

The Dallas lockbox facility operates as a sorting and intake center, not an adjudication center. When your package arrives, lockbox staff verify that the envelope contains a STEM OPT application, log the receipt date, open the package, conduct an initial completeness check, collect the filing fee, scan the documents, and forward the file to a USCIS service center for adjudication.

The lockbox does not make decisions about your application. It does not issue approvals or denials. It does not respond to case status inquiries or requests for expedited processing. The lockbox's role ends once your application enters the USCIS electronic case management system and transfers to a service center.

Your receipt notice — Form I-797C, Notice of Action — will bear the USCIS service center address where your case was routed for adjudication, not the Dallas lockbox address. That service center becomes your point of contact for all case inquiries, Requests for Evidence (RFEs), and interview scheduling if USCIS requires one. The lockbox itself has no public phone line and does not accept walk-in visits.

How USCIS Assigns Receipt Dates at the Lockbox

The receipt date — the date USCIS officially considers your application filed — is the date the lockbox physically receives your package, not the date you mailed it or the postmark date. This is critical for STEM OPT applicants, because the application must be received by USCIS no later than the date your current OPT work authorization expires. A postmark before the deadline does not satisfy the requirement if delivery occurs after the deadline.

USCIS does not grant filing-date credit for packages delayed by the carrier, weather, or misrouting. The applicant bears the risk of late delivery. For applications approaching the OPT expiration date, this is why many filers use commercial courier services with guaranteed delivery dates and tracking rather than standard USPS mail.

Once the lockbox logs your receipt date, USCIS generates a receipt notice within approximately two to four weeks. The receipt notice contains your case number (starting with the prefix EAC, WAC, or LIN, depending on the service center) and confirms that USCIS accepted your application for processing. If the lockbox rejects your application due to an incorrect fee, missing signature, or incomplete form, you will receive a rejection notice instead, and your package will be returned unprocessed.

Here's the Honest Answer: The Lockbox Will Not Fix Your Filing Mistakes

Applicants often assume that the lockbox staff will contact them if the application is missing a document or contains a minor error, giving them a chance to correct it. They will not. The lockbox applies a completeness check based on USCIS filing standards: if the required fields on Form I-765 are blank, if the filing fee is incorrect, if the supporting documents listed in the instructions are missing, or if the form version is outdated, the entire package is rejected and mailed back to you. There is no opportunity to supplement a rejected application — you must refile from scratch.

Rejection notices take time to generate and mail, often two to three weeks. If your OPT work authorization expires during that window, you lose work authorization, and the automatic 180-day extension available to timely STEM OPT filers does not apply because USCIS never accepted your application as timely filed. The error is unrecoverable except by refiling, which now happens after your original OPT has lapsed.

The lockbox is a processing bottleneck by design. It exists to route thousands of applications daily to the correct adjudication centers, not to provide applicant support or filing assistance. Errors that would be immediately visible to you during an in-person filing — a missing page, a blank required field, an unsigned form — become grounds for outright rejection when filed by mail.

The Comparison: USPS Mail vs. Commercial Courier

Both methods work if used correctly. The choice depends on how much time remains before your OPT work authorization expires and how much risk you are willing to accept that weather, sorting delays, or carrier error will cause a missed deadline.

What If I Already Mailed My STEM OPT Application to the Wrong Address?

If you realize after mailing that you used the courier address for a USPS package, or vice versa, your best option is to track the package and determine whether it has been delivered. If the package is still in transit, contact the carrier immediately and attempt to reroute it to the correct address. USPS allows rerouting through Package Intercept for a fee; FedEx and UPS offer similar services. Rerouting is not guaranteed to succeed, but it is faster than waiting for the package to be returned as undeliverable.

If the package has already been delivered to the wrong facility, USCIS will not forward it internally. The lockbox or receiving office will treat it as misfiled and return it to you. You will receive the package back with no action taken, and you must refile using the correct address. The original mailing date does not count as your filing date.

In this situation, if your OPT expiration is approaching, consult an immigration attorney immediately. The Law Offices of Peter D. Chu evaluates these scenarios during consultations and can determine whether you have time to refile, whether you qualify for the 180-day automatic extension, and what steps preserve your work authorization. The $250 consultation fee covers case-specific guidance on filing strategy and deadline risk.

What If I Am Outside the U.S. When I Need to File?

STEM OPT extension applications require that the applicant be physically present in the United States when USCIS receives the application. If you are abroad when your current OPT is set to expire, you cannot file a STEM OPT extension by mailing it to the lockbox from overseas. USCIS will reject the application on jurisdictional grounds.

You must return to the U.S. before your OPT expires and file the extension from within the country. If your OPT expires while you are abroad, you lose work authorization, and the STEM extension becomes unavailable. The remedy at that point is either to qualify for a different visa category or to depart and pursue a new F-1 admission if you remain enrolled in an academic program.

Some applicants attempt to file by having a friend or family member mail the application from the U.S. on their behalf. This does not cure the physical presence requirement. USCIS may issue a Request for Evidence asking you to document your location on the filing date, and if you cannot prove U.S. presence, the application will be denied.

What If the Lockbox Rejects My Application for an Incorrect Fee?

As of 2026, the Form I-765 filing fee for STEM OPT applicants is set by USCIS fee rules and listed on the current fee schedule at uscis.gov/forms. Fees change periodically, and an application submitted with an outdated fee amount will be rejected. USCIS does not accept partial payments or contact applicants to request the balance.

If the lockbox rejects your application for an incorrect fee, the package is returned to you with a rejection notice explaining the deficiency. You must submit a new application with the correct fee. The rejection notice typically arrives two to three weeks after USCIS received the original package.

To avoid fee-related rejections, verify the current I-765 filing fee on the USCIS website immediately before mailing. Pay by check or money order made payable to "U.S. Department of Homeland Security." Do not abbreviate the payee name, and do not send cash. Include your full name and case number (if you have one from a prior filing) on the check memo line.

The Required Supporting Documents for STEM OPT Lockbox Filing

The lockbox completeness check verifies that your package includes the documents listed in the Form I-765 instructions for STEM OPT applicants. Missing any required document results in rejection. As of 2026, required documents include:

• Completed and signed Form I-765, using the current version listed on uscis.gov
• Copy of your current EAD card (front and back) showing your initial OPT work authorization
• Copy of your most recent Form I-20 endorsed by your Designated School Official (DSO) for STEM OPT
• Copy of your STEM degree (diploma or official transcript showing degree conferral)
• Employer's completed and signed Form I-983, STEM OPT Training Plan
• Two passport-style photographs meeting USCIS photo requirements
• Filing fee (check or money order)
• Copy of your passport biographical page and any U.S. visa pages

The I-983 must bear original signatures from both you and your employer, and the employer's E-Verify Company Identification Number must appear on the form. USCIS will reject applications with unsigned or incomplete I-983 forms. The training plan must also describe STEM-specific learning objectives tied to your degree field.

Place all documents in a single envelope. Do not bind, staple, or punch holes in the documents. Use paper clips if you need to group related pages. Include a cover letter summarizing the contents of the package, though the cover letter itself is not required.

The STEM OPT Cap-Gap Extension and Lockbox Filing

If your employer filed an H-1B petition on your behalf and you qualify for cap-gap extension of your F-1 status and work authorization, you still file your STEM OPT extension to the Dallas lockbox using the addresses above. The cap-gap extension does not change the filing address or procedure.

Cap-gap applies when your OPT period would otherwise expire before your H-1B status begins on October 1. USCIS automatically extends your F-1 status and EAD through September 30 or until USCIS adjudicates your H-1B petition, whichever comes first. If you are also eligible for a STEM OPT extension, filing that extension preserves work authorization beyond the cap-gap period if your H-1B is denied or if you withdraw from the H-1B process.

Your DSO must update your Form I-20 to reflect the cap-gap extension before you file the STEM OPT extension. The lockbox will verify that your I-20 shows an extended program end date. An I-20 that does not reflect cap-gap eligibility can result in a STEM OPT denial even if you filed timely.

Contact the Law Offices of Peter D. Chu for STEM OPT Filing Guidance

Filing deadlines, address requirements, and document checklists leave no margin for error in STEM OPT extension cases. A rejected application filed days before your OPT expires can end your work authorization and force you out of status. The Law Offices of Peter D. Chu, located at 4615 Convoy St, San Diego, CA 92111, provides consultations on STEM OPT filing strategy, document review, and deadline management. The consultation fee is $250. Call 858-268-8823 or visit peterchu.com to schedule.

The firm's immigration attorneys review your Form I-765, verify that your I-983 training plan meets USCIS standards, confirm that your I-20 endorsements are current, and ensure your package is complete before you mail it. This review is not legal advice applicable to your specific case until you retain the firm, but it identifies the deficiencies that cause lockbox rejections before they happen.

Disclaimer: This article provides general information about USCIS lockbox addresses and STEM OPT extension filing procedures. It is not legal advice and does not create an attorney-client relationship between the reader and the Law Offices of Peter D. Chu. Immigration outcomes depend on individual facts, and procedural requirements change periodically. Consult a licensed immigration attorney before filing any application with USCIS.

Schedule a consultation with the Law Offices of Peter D. Chu — 4615 Convoy St, San Diego, CA 92111 · 858-268-8823 · Mon–Fri, 8:30 AM–5:30 PM. Consultation fee: $250.