A proforma invoice and a Letter of Credit (LC) are inseparable in high-value export transactions. The buyer uses your proforma invoice to instruct their bank to open the LC. If the proforma is inaccurate or incomplete, the LC will be issued with wrong terms — and when you present shipping documents, the bank will find discrepancies and refuse payment.

What is a Letter of Credit?

A Letter of Credit is a bank guarantee. The buyer's bank promises to pay the seller, on behalf of the buyer, when the seller presents the correct documents (commercial invoice, bill of lading, packing list, certificate of origin, etc.) within the LC's terms. It protects the seller against non-payment and the buyer against non-delivery.

How the proforma invoice triggers the LC

  1. Seller issues a proforma invoice with full details (HS codes, Incoterms, ports, value, payment terms)
  2. Buyer takes the proforma to their bank and applies for an LC
  3. Buyer's bank opens the LC, copying the terms from the proforma
  4. Seller receives LC, verifies it matches the proforma exactly
  5. Seller ships goods and presents documents to their bank within LC validity
  6. Buyer's bank pays seller's bank (at sight or on the usance date)

Fields on the proforma that must exactly match the LC

Proforma fieldWhy it must match
Product descriptionBank compares commercial invoice description word-for-word against LC
HS codeUsed by bank for commodity risk and customs cross-check
Total valueLC amount must equal or exceed proforma total — cannot present over LC amount
CurrencyLC and all documents must be in the same currency
Incoterms + named placeBill of lading must match: "FOB Shanghai" ≠ "FOB China"
Port of loadingShipping documents must show same port as stated in LC/proforma
Port of dischargeSame — any variation causes discrepancy
Latest shipment dateBill of lading date must be on or before this date
Validity dateLC expiry must allow enough time after shipment to present documents
Seller name and addressMust match exactly as it appears in the LC beneficiary field

Common LC discrepancies caused by a wrong proforma

How to issue an LC-ready proforma invoice

  1. Use the exact legal name of your company — match it to your bank account.
  2. State Incoterms with the exact named place: "FOB Shanghai Port" not "FOB China."
  3. Include HS codes on every line item.
  4. Set validity to match your LC timeline — typically 90 days.
  5. State the port of loading and discharge precisely.
  6. Agree the LC amount to include all charges (freight, insurance) — do not let the LC be opened for less than your invoice total.
  7. When you receive the LC, read every term before starting production. If anything conflicts with the proforma, request an LC amendment immediately — amendments are much easier before shipment than after.

Use our export proforma invoice guide for a full checklist of export fields. Download a free proforma invoice template with all LC-required fields pre-formatted.