Cross-border commodity trade has a standing problem: the seller won't release a cargo on a stranger's promise, and the buyer won't prepay a stranger for cargo unseen. The letter of credit is the machine built to solve it, banks substituting their credit for their customers', paying against documents under rules the whole world shares. This page is the plain-language version for fuel and crude deals: how the machine works, the variants that matter, where it jams, and how to spot the fakes. Education, not legal or banking advice; structure real deals with your bank and counsel.
The machine: pay against paper
The cast is four: the buyer (applicant) asks its bank to issue the credit; the issuing bank commits to pay; the seller (beneficiary) ships and presents documents; an advising or confirming bank in the seller's country handles, and optionally guarantees, the seller's end. The engine's single moving part is document examination: the credit lists exactly what paper must appear, commercial invoice, bills of lading, inspection certificates of quantity and quality, insurance, whatever the deal requires, and the bank pays when a complying presentation arrives within the credit's deadlines. The bank never sees the cargo and doesn't care about it: documents comply, payment flows, even if the buyer has changed its mind; documents don't comply, no obligation, even if the cargo is perfect. That independence, standardized in the UCP 600 rulebook banks operate under, is the whole magic: each side trusts the machine instead of the stranger.
The variants that matter
Timing first: a sight credit pays on presentation, the seller's preference; a usance credit pays at tenor, 30, 60, 90 days after shipment or presentation, financing the buyer while leaving the seller a bank obligation that can usually be discounted into immediate cash for a fee. Strength second: an unconfirmed credit is a promise from the issuing bank alone, which means the seller is carrying that bank's credit and its country's transfer risk; confirmation adds a bank in the seller's own market that must pay against the same documents regardless of what happens to the issuer, and sellers into difficult banking jurisdictions treat it as standard equipment. Structure third: the documentary credit routes every shipment's paper through the banks, while the standby letter of credit inverts the logic, sitting quietly behind an open-account relationship as a guarantee drawn only on failure to pay, the usual architecture for repeat business like recurring fuel shipments once counterparties know each other. Below the LC on the security ladder sit documentary collections, banks passing documents against payment without guaranteeing anything, and credit-insured open account, each cheaper and weaker, each fine in its place.
Where the machine jams: discrepancies
The LC's strength is its literalism, and so is its failure mode. Banks examine documents strictly, and a large share of first presentations worldwide arrive discrepant: a name spelled differently than the credit, a late shipment date, a missing signature, an inspection certificate that doesn't echo the credit's wording. A discrepancy converts the bank's obligation into the buyer's option, payment now needs a waiver, which is a bad place to discover you're renegotiating. The defense is craft, not luck: review the credit's terms the day it arrives and amend what can't be met; write the credit's document list from what the inspectors and carrier will actually produce; prepare the presentation against a checklist before the vessel sails; and present early enough inside the credit's deadlines to cure problems. Operations that treat the LC checklist as part of cargo readiness collect at sight; operations that treat it as paperwork learn what a waiver costs.
The fakes, and the five-minute screen
Wherever real instruments move money, fake ones chase the gullible, and the commodity world has a full bestiary: leased instruments sold as if a rented promise were spendable, screenshot LCs that no bank will authenticate, non-operative drafts pushed as binding, and procedures that demand performance before any verifiable bank undertaking exists, the same inverted logic that flags fake crude cargoes. The screen is short and lethal to all of it: real instruments arrive bank-to-bank through authenticated channels, name banks that exist and answer, and survive your own bank's verification, so the standing rule is that nothing counts until your bank says it counts. A counterparty who resists that check, hurries it, or explains why the usual channels don't apply to this special deal has told you everything a diligence file needs to know.
Common questions
What does an LC cost?
Issuance, advising, confirmation, and negotiation fees typically sum to a small percentage of the credit's value, rising with tenor, confirmation, and the issuing bank's risk. Priced against the alternative, shipping tanker-sized value on trust, it's among the cheapest insurance in the trade.
Who writes the credit's terms?
The contract should: a good sale agreement specifies the LC's required documents, deadlines, and banks before issuance, so the credit arrives matching the deal instead of surprising it. Sellers who let buyers' banks draft unsupervised inherit whatever the template said.
Are LCs only for the first deal?
Often, in practice: relationships commonly start on confirmed sight LCs and graduate to standbys over open account as trust and volume build. The instrument ladder is a relationship ladder, climbed one clean transaction at a time.
Where Vexon fits
Vexon structures its export and cargo business on bank instruments matched to the counterparty and corridor, with the documentation discipline this page describes, on the international desk: get in touch to talk terms.