PSC vs Protest: Which One Applies? (Decision Tree by Liquidation Status)

2026 context: The Supreme Court held IEEPA doesn’t authorize tariffs and CBP stopped collecting IEEPA duties effective Feb. 24, 2026, but refund paths for past entries still rely on liquidation-driven procedures (PSC vs protest). (Opinion PDF, CBP CSMS #67834313)

Informational only — not legal advice.

1) Definitions (in operational English)

What “liquidation” means (why it’s the fork in the road)

Liquidation is CBP’s final computation/assessment of duties on an entry — the point at which the amounts become final unless you take timely action. CBP’s protest guidance is built around this concept: after liquidation, the statutory protest clock matters. (CBP — Protests)

PSC (Post Summary Correction)

CBP describes PSC as the method for trade to electronically correct entry summaries prior to liquidation. It is submitted through ACE by an authorized entry summary filer. (CBP — Post Summary Correction)

CBP also describes PSC as “essentially a new entry summary” and notes that it will not be processed until it is fully paid. (CBP — Post Summary Correction)

Protest (CBP Form 19 / electronic protest)

CBP’s protest guidance describes protests as the way importers (or their broker/attorney) contest CBP decisions — and highlights that the protest timeline is generally within 180 days of liquidation. (CBP — Protests)

The statute governing protest timing is 19 U.S.C. §1514. (19 U.S.C. §1514)

2) The decision tree (PSC vs protest)

Use this as a practical flow. It is intentionally conservative.

Step 0 — Do you have the entry number(s)?

If you don’t have entry numbers, you can’t reliably determine liquidation status or build a filing calendar. Your first step is to obtain entry summaries (Form 7501 PDFs or ACE exports) from ACE or your broker/carrier.

CBP’s Form 7501 overview page is a good “anchor” reference for the document name. (CBP Form 7501 overview)

Step 1 — Is the entry liquidated?

If YES (liquidated): start with a protest workflow.

• CBP summarizes that a protest is generally filed “within 180 days of liquidation.” (CBP — Protests)
• The statute provides the 180‑day rule tied to liquidation/reliquidation (with an alternate clock where liquidation is “inapplicable”). (19 U.S.C. §1514)

If NO (not liquidated): PSC may be available — but only if you’re within CBP’s PSC timing windows and other criteria.

Step 2 — If not liquidated: is a PSC still timely?

CBP states a PSC filer can submit changes:

• within 300 days from the date of entry, and
• up to 15 days of the scheduled liquidation date, whichever date is earlier.

If outside those windows, ACE will reject the PSC (per CBP). (CBP — Post Summary Correction)

Practical takeaway: you need two dates for each entry:

1. entry date, and
2. scheduled liquidation date (or at least a reliable proxy for whether liquidation is near).

Step 3 — If PSC is timely: do you meet CBP’s other criteria?

CBP lists PSC criteria such as (paraphrased): the entry summary must be accepted, not under CBP review, in CBP control, and paid; and the entry summary cannot be liquidated. (CBP — Post Summary Correction)

If you don’t meet those criteria, PSC may not be usable (and you should not assume you can “just file PSC anyway”).

3) What this means for IEEPA tariff refunds (without overpromising)

In the IEEPA refund context, the “PSC vs protest” question usually shows up as:

• “Can I correct the entry summary before liquidation so the duty computation excludes the IEEPA amount?” or
• “Do I need to protest after liquidation to preserve a refund claim?”

CBP’s public guidance does not provide a single universal “refund button.” Instead, it describes existing mechanisms (PSC and protests) and ties them to liquidation status. Start with CBP’s overview pages and confirm with your broker/counsel for your specific entries. (CBP — Post Summary Correction, CBP — Protests)

For most IEEPA refund scenarios, the decision tree is straightforward once you have liquidation status. The complexity usually comes from mixed portfolios — some entries liquidated, some not — requiring both paths in parallel.

4) A scalable workflow for many entries (the part that saves time)

If you have dozens/hundreds of entries, treat this like a triage problem:

1. Build an entry list (entry number, entry date, IOR, port, broker).
2. Add liquidation status/date (or “scheduled liquidation” if you have it).
3. Split into three buckets:
   • Bucket A — liquidated: needs protest calendar and filing workflow.
   • Bucket B — unliquidated + PSC‑eligible: coordinate with broker on PSC windows and submission.
   • Bucket C — unliquidated but PSC‑ineligible / unclear: escalate for review; don’t assume no options.

If you’re missing liquidation status, do not try to infer from delivery dates. CBP decisions are entry‑specific and procedural timelines attach to entry status, not shipment arrival.

5) Common pitfalls (and how to avoid them)

• Using shipment/delivery dates as substitutes for entry dates. PSC timing and protest timing are tied to CBP entry/liquidation concepts. (CBP — Post Summary Correction, CBP — Protests)
• Waiting too long to ask your broker. PSC has explicit timing windows, and CBP states ACE will reject PSCs filed outside those windows. (CBP — Post Summary Correction)
• Assuming PSC works after liquidation. CBP states that if it’s liquidated, options to correct are a prior disclosure or a protest. (CBP — Post Summary Correction)
• Not having “payment readiness” set up. Even after a successful administrative path, refunds can still be delayed if your refund payment setup is incomplete (for example, electronic refunds/ACH configuration). (CBP — ACH Refunds FAQs)

6) What to do now (practical next steps)

1. Get your entry list (7501 PDFs, ACE exports, or broker data).
2. Add liquidation status/date fields.
3. Calendar deadlines conservatively (especially the 180‑day protest clock tied to liquidation).
4. If you have unliquidated entries, ask your broker specifically about PSC windows and whether they can submit PSCs on your behalf.