What Is a Letter of Credit and Why Does It Matter?

International trade involves a fundamental problem: the buyer and seller are in different countries, often separated by thousands of miles, different legal systems, and limited ability to verify each other's trustworthiness. The buyer worries about paying for goods that never arrive. The seller worries about shipping goods and never receiving payment.

A letter of credit (LC) solves this problem by inserting banks into the transaction as trusted intermediaries. The buyer's bank guarantees payment to the seller, provided the seller presents documents that conform exactly to the terms specified in the LC. The bank does not inspect the physical goods — it only examines documents. If the documents match the LC requirements, the bank pays. If they do not, the bank refuses.

This document-centric nature of letters of credit is what makes the proforma invoice so critical. The proforma invoice for LC transactions sets the terms that flow into the letter of credit itself, and every subsequent document must align with what the proforma originally stated.

The Role of the Proforma Invoice in the LC Process

A proforma invoice letter of credit connection begins at the very start of a transaction. Here is how it works in practice.

The seller sends the buyer a proforma invoice containing product details, pricing, shipping terms, and all the commercial information about the proposed sale. The buyer takes this proforma invoice to their bank and requests that a letter of credit be opened in favor of the seller. The bank uses the proforma invoice as the basis for drafting the LC terms and conditions.

Once the LC is issued, the seller reviews it to confirm that the terms match what was agreed. The seller then ships the goods and prepares a set of documents — including the commercial invoice, packing list, bill of lading, and any required certificates — that must conform precisely to the LC terms. These documents are presented to the seller's bank, which forwards them to the buyer's bank for examination.

The proforma invoice for LC purposes is therefore the seed document from which the entire transaction grows. Errors or ambiguities in the proforma propagate through the LC and into every subsequent document, creating discrepancies that banks use as grounds to refuse payment.

Understanding UCP 600: The Rules That Govern Letters of Credit

Letters of credit worldwide are governed by the Uniform Customs and Practice for Documentary Credits, commonly known as UCP 600. Published by the International Chamber of Commerce, UCP 600 has been the standard reference since its adoption in 2007. Understanding a few key principles from UCP 600 helps explain why proforma invoices must be prepared with extreme care.

The Principle of Strict Compliance

Banks examine documents on their face to determine whether they comply with LC terms. Under UCP 600, compliance must be strict — not substantial, not approximate, but strict. A misspelling in the company name, a weight discrepancy of a few kilograms, or a shipping date one day outside the allowed window can all constitute grounds for refusal.

This principle means that whatever information appears on your proforma invoice for LC purposes must be reproducible with perfect accuracy on every subsequent document. If your proforma says the goods weigh 2,450 kilograms, your packing list and bill of lading must also say 2,450 kilograms — not 2,448 and not 2,452.

Banks Deal in Documents, Not Goods

UCP 600 makes clear that banks deal with documents alone and do not concern themselves with the underlying goods or services. A bank will pay against compliant documents even if the physical goods turn out to be defective. Conversely, a bank will refuse payment for non-compliant documents even if the goods are exactly as ordered.

This principle reinforces why getting your proforma invoice letter of credit details right matters more than almost anything else in the transaction. The documents are the transaction, as far as the banks are concerned.

Independence Principle

The LC is a separate obligation from the underlying sales contract. Even if the buyer and seller agree to modify the terms of their deal, those modifications do not affect the LC unless the LC itself is formally amended. This means that if your proforma invoice stated one set of terms and you later agree with the buyer to change something, you must also arrange for the LC to be amended accordingly.

Step-by-Step LC Workflow with a Proforma Invoice

Here is the complete workflow for a letter of credit transaction, showing where the proforma invoice fits in at each stage.

Step 1: Negotiate and Issue the Proforma Invoice

The seller and buyer agree on product specifications, pricing, quantity, Incoterms, shipping method, and payment terms. The seller issues a proforma invoice for LC application, containing every detail the buyer's bank will need to draft the letter of credit.

Step 2: Buyer Applies for the LC

The buyer submits the proforma invoice to their bank (the issuing bank) along with an LC application form. The bank evaluates the buyer's creditworthiness and, if approved, issues the letter of credit according to the terms reflected in the proforma invoice.

Step 3: LC Is Transmitted to the Seller's Bank

The issuing bank sends the LC to a bank in the seller's country (the advising bank or confirming bank). This bank authenticates the LC and forwards it to the seller.

Step 4: Seller Reviews the LC

This is a critical step. The seller must compare every detail of the received LC against the original proforma invoice. Any discrepancy — a different product description, an incorrect Incoterm, a wrong currency — must be resolved through an LC amendment before the seller ships goods.

Key items to verify include:

Beneficiary name and address match the seller's legal entity exactly
Product descriptions match the proforma invoice word for word
Quantities and unit prices align with the proforma
Incoterms are correctly stated with the named place
Shipping deadline is achievable given production and logistics timelines
Document requirements are obtainable (do not accept an LC that requires a document you cannot produce)
Expiry date allows sufficient time for document preparation and presentation

Step 5: Seller Ships Goods and Prepares Documents

After confirming the LC terms are acceptable, the seller arranges shipment and prepares the required document set. Common documents include the commercial invoice, packing list, bill of lading or airway bill, certificate of origin, insurance certificate, and inspection certificate.

Every document must conform to the LC terms, which in turn should mirror the proforma invoice.

Step 6: Document Presentation

The seller presents the complete document set to their bank within the time limit specified in the LC (typically 21 days after shipment, but this varies). The bank examines the documents for compliance.

Step 7: Bank Examination and Payment

The advising or confirming bank forwards the documents to the issuing bank. The issuing bank has five banking days under UCP 600 to examine documents and decide whether they comply. If compliant, the bank releases payment to the seller. If discrepancies are found, the bank notifies the presenter and may refuse payment.

Step 8: Buyer Receives Documents and Goods

Upon honoring the LC, the issuing bank releases the documents to the buyer. The buyer uses the bill of lading to claim the goods from the shipping line or freight forwarder.

What Banks Require on a Proforma Invoice for LC

Banks have specific expectations when reviewing a proforma invoice submitted as the basis for an LC application. While requirements vary by institution and country, most banks expect the following elements.

Complete Seller and Buyer Details

Full legal names, registered addresses, and identification numbers. The seller's name on the proforma becomes the beneficiary of the LC, so it must match the entity that will ultimately present documents for payment.

Unambiguous Product Descriptions

Banks prefer clear, specific descriptions that can be verified against shipping documents. Avoid trade jargon or abbreviations that might be interpreted differently by document examiners at different banks.

Precise Pricing and Totals

Unit prices, quantities, and the total LC value must be clearly stated. Banks typically allow a tolerance of plus or minus five percent on quantity and amount unless the LC specifies otherwise, but the proforma should state exact figures.

Shipping Terms and Timeline

The Incoterm, port of loading, port of discharge, and latest shipment date should all be clearly specified. Banks incorporate these into the LC terms, and any inability to meet the shipping deadline will require an amendment.

Required Documents List

Experienced sellers include on their proforma invoice a list of documents they can provide. This helps the buyer instruct their bank on which documents to require, avoiding situations where the LC demands a document the seller cannot obtain.

Validity Period

The proforma invoice should state how long the quoted terms remain valid. This gives the buyer a timeframe within which to arrange the LC.

Common Mistakes That Cause LC Rejections

The International Chamber of Commerce has reported that a significant proportion of first presentations under letters of credit contain discrepancies. Many of these discrepancies trace back to errors or ambiguities in the original proforma invoice.

Inconsistent Product Descriptions

If your proforma invoice describes goods as "hydraulic cylinders, double-acting, 50mm bore" but your commercial invoice later says "hydraulic actuators, 50mm," the bank may treat this as a discrepancy. Use identical descriptions across all documents.

Name and Address Mismatches

Corporate names must be exactly consistent. "ABC Trading Co., Ltd." is not the same as "ABC Trading Company Limited" in the eyes of a document examiner applying strict compliance standards. Settle on one exact form of your company name and use it everywhere.

Arithmetic Errors

If your proforma shows 1,000 units at $15.00 each but the total reads $14,500 instead of $15,000, this creates a discrepancy. Banks check arithmetic, and errors undermine confidence in the entire document set.

Incoterm Errors

Writing "FOB" without specifying the port, or using an outdated Incoterm from a previous edition, creates ambiguity. Always use the current ICC Incoterms edition and include the named place.

Missing or Incorrect Shipping Details

The proforma invoice should specify realistic shipping dates, ports, and methods. If the LC incorporates an unrealistic shipping deadline from the proforma, the seller will be unable to comply and will need to request an amendment — which costs time and money.

Failing to Account for LC Costs

Letters of credit involve bank fees on both sides of the transaction. Sellers should factor these costs into their pricing when preparing the proforma invoice. Common fees include issuance fees, advising fees, confirmation fees, amendment fees, and discrepancy fees.

Tips for a Successful Proforma Invoice Letter of Credit Transaction

Based on decades of collective trade finance experience, here are the practices that separate smooth LC transactions from troubled ones.

Draft the proforma invoice as if it were the commercial invoice — the closer these two documents are in format and detail, the fewer discrepancies will arise
Specify which Incoterms edition you are using — currently Incoterms 2020
Include a tolerance clause if quantities or values might fluctuate slightly, such as "quantity plus or minus five percent at seller's option"
List every document you can provide and flag any that might be difficult to obtain, so the buyer can adjust the LC requirements accordingly
Allow adequate time between the latest shipment date and the LC expiry date for document preparation and presentation
Review the LC immediately upon receipt and request amendments for any discrepancies before shipping
Use a consistent document template across all trade documents to minimize formatting differences that might confuse document examiners
Work with your bank's trade finance department early in the process — they can advise on common pitfalls specific to your transaction type and destination country

When to Use a Letter of Credit vs. Other Payment Methods

Letters of credit are not the right choice for every transaction. They involve bank fees, administrative effort, and processing time that may not be justified for small orders or transactions between well-established trading partners.

Consider using an LC when:

You are dealing with a new buyer or supplier for the first time
The transaction value is significant relative to your business
The destination country has currency controls or political instability
The buyer's creditworthiness is uncertain
The goods are manufactured to custom specifications and cannot easily be resold

For smaller or repeat transactions, alternatives like documentary collections, open account terms, or advance payment may be more practical. However, whenever an LC is warranted, investing the time to prepare a thorough proforma invoice for LC purposes pays dividends in smooth processing and timely payment.

Final Thoughts

The proforma invoice for letter of credit transactions occupies a unique position in international trade documentation. It is both a commercial document and a financial instrument — the blueprint from which banks construct the payment mechanism that protects both buyer and seller.

Treat your proforma invoice with the precision it deserves. Every description, every number, every term will be scrutinized by banking professionals whose job is to find discrepancies. By getting the proforma right, you set the foundation for a transaction that flows smoothly from quotation through shipment to payment, with no surprises along the way.

Related Resources

Create your invoice proforma online — free — complete guide and free generator with all LC-required fields
Proforma invoice for export — Incoterms, HS codes, and export documentation guide
Proforma invoice for customs clearance — step-by-step customs compliance checklist
Free proforma invoice template — download as PDF, Word, or Excel with all bank-required fields

Proforma Invoice for Letter of Credit: Bank Requirements, UCP 600 & LC-Ready Template (2026)