Letters of Credit for Polymer Trade: A Practical Guide

A documentary letter of credit converts an open question — *will this buyer actually pay for 200 tonnes of HDPE shipped halfway around the world?* — into a narrower, more answerable one: *will the documents comply with the credit?* The buyer's bank (the issuing bank) substitutes its own creditworthiness for the buyer's, undertaking to pay the seller against a defined set of compliant documents. The instrument is governed almost universally by the ICC Uniform Customs and Practice for Documentary Credits, UCP 600, and its defining principle is austere: banks deal with documents, not with goods (UCP 600 Article 5). The resin can be exactly as contracted and still go unpaid on a discrepancy; conversely, clean documents oblige the bank to pay even if a downstream dispute is brewing.

That trade-off — bank risk in place of counterparty risk, paid for with fees and paperwork discipline — is the whole case for an L/C. It sits at the secure-but-costly end of the payment-terms spectrum, well above open account and cash against documents in both protection and price. The mechanics reward sellers who can produce a flawless document set on a tight clock and punish those who cannot. This guide walks the cycle, the required documents, the discrepancy trap, the confirmed-versus-unconfirmed decision, and where the cost actually lands.

The documentary credit cycle, step by step#

The sequence is fixed and worth internalising, because every fee and every risk attaches to a specific step. The buyer and seller first agree the underlying sales contract — grade, quantity, Incoterms 2020 rule, price and the fact that payment will be by L/C, including who confirms it and who pays which fees. The buyer then instructs its bank to issue the credit in the seller's favour.

• —Issuance — the issuing bank opens the credit and transmits it (usually by SWIFT MT700) to a bank in the seller's country.
• —Advising — the advising bank authenticates the credit and passes it to the seller (the beneficiary). It takes on no payment liability unless it also confirms.
• —Confirmation (optional) — if requested, a confirming bank adds its own irrevocable undertaking to pay against compliant documents.
• —Shipment — the seller ships on or before the latest shipment date and obtains the transport document (bill of lading or multimodal document).
• —Presentation — the seller presents the full document set to the nominated or confirming bank before expiry and within the presentation period.
• —Examination — banks have a maximum of five banking days following the day of presentation to determine compliance (UCP 600 Article 14(b)).
• —Settlement — on compliant documents the bank pays at sight or accepts/defers per the credit's terms; documents are released to the buyer to clear the goods.

The applicant is the buyer; the beneficiary is the seller. A credit may be available by payment, acceptance or negotiation, and may be at sight (paid on compliant presentation) or usance/deferred (paid at a stated tenor, e.g. 90 days from the B/L date). Usance credits are effectively supplier financing — the buyer gets a payment delay while the seller can often discount the accepted draft for early cash.

The required document set for a polymer shipment#

The credit lists every document the seller must present and, critically, what each must say. The governing rule under UCP 600 Article 14(d) is consistency: data in one document must not conflict with data in another or with the credit itself. Grade designation, quantity, weights, marks and the description of goods should read identically across the invoice, packing list, bill of lading and certificate of analysis. The table below maps the typical set and the points where polymer shipments most often trip.

Two recurring polymer-specific snags deserve flagging. First, the goods description on the commercial invoice must correspond with the credit (Article 18(c)) — a credit that says "HDPE film grade, MFI 0.05 g/10 min (ISO 1133), 200.00 MT" must be invoiced in those terms, not paraphrased. On every other document a description "in general terms not in conflict" with the credit is acceptable, but the invoice has no such latitude. Second, the certificate of analysis must report values inside the contracted ranges; an MFI or density figure that drifts outside spec is both a quality problem and a documentary discrepancy.

Discrepancies: where L/Cs actually go wrong#

A large share of first presentations are rejected on first pass for discrepancies — typographical mismatches, late shipment, expired credit, missing endorsements, weights that do not reconcile. The point worth hammering: a discrepancy releases the bank from its obligation to pay. It is no longer the bank's problem; it becomes the seller's. The bank examines, and if it decides to refuse it must give a single notice no later than the close of the fifth banking day following presentation, stating each discrepancy and the disposition of the documents (UCP 600 Article 16(c) and (d)).

Under an L/C the goods can be sitting clean on the quay and the seller still goes unpaid on a misplaced comma — banks pay against documents, not against resin.

When documents are found discrepant, the beneficiary has limited moves, and time is usually the binding constraint. If the expiry and presentation period still allow, correct and re-present. If not, ask the presenting bank to approach the applicant for a waiver of the discrepancies — but a waiver is the buyer's discretion, not a right, and a buyer in a falling market may use it to renegotiate or walk. The last resort is to switch to a documentary collection basis, where the bank handles documents but gives no payment undertaking. The defence is preventive: a meticulous checklist, a draft-document review against the credit before shipment, and shipment and expiry dates with genuine slack built in.

• —Reconcile grade, quantity, weights and marks across every document before presenting.
• —Ship on or before the latest shipment date; present inside the expiry and the presentation period (default 21 days from the B/L date, UCP 600 Art. 14(c)).
• —Confirm the B/L is clean and marked 'shipped on board' with the correct notify party and consignee.
• —Check insurance is at least 110% of the CIF/CIP value in the credit's currency (Art. 28(f)).
• —Read the credit on receipt — request amendments for any term you cannot meet *before* you ship, not after.

Confirmed vs unconfirmed — and what it costs#

An unconfirmed credit gives the seller only the issuing bank's promise. If that bank is small, opaque, or sits in a country with transfer restrictions or political risk, the promise is only as good as the bank and the jurisdiction behind it. Confirmation solves this: a second bank — typically in the seller's country or a major financial centre — adds its own irrevocable undertaking, so the seller looks to a counterparty it can actually assess. The trigger to confirm is straightforward: you cannot price the issuing bank's or the country's risk, or you simply will not carry it. This is a frequent calculus when sourcing into or out of higher-risk corridors.

Stack these and an L/C commonly costs an indicative 0.5–3% of contract value, with confirmation the largest swing factor on a risky issuing bank. That is the number to weigh against the protection gained. On a first transaction with an unknown buyer, or into a jurisdiction with FX-transfer risk, a confirmed L/C is cheap insurance. On a repeat lane with a creditworthy counterparty, the same fees are dead weight against open account or cash against documents. The fee split between applicant and beneficiary is a contract term, not a law of nature — fix it in the sales agreement before the credit is opened, alongside who confirms and on which bank.

When the L/C is the right tool — and when it isn't#

Use a documentary credit when counterparty or country risk is real and unhedged: a new relationship, a large first order, a buyer whose balance sheet you cannot see, or a destination with transfer or political risk. It is also the natural instrument when the buyer needs the goods released against documents but the seller will not ship on trust. Avoid it when the relationship and the lane are proven — the fees and the document discipline buy protection you no longer need, and cash against documents or open account moves faster and cheaper. The deciding question is never "is the buyer honest?" but "if the documents are clean, who is contractually bound to pay, and can I assess that party?" Get the credit's terms — shipment date, expiry, document list, descriptions, confirmation — right at issuance, present a flawless set, and the L/C does exactly what it promises. Need a payment structure built around your specific lane and counterparty? Talk to the OmniaStrata desk.