What Discover Reason Code LT Means
Discover reason code LT — Illegible Transaction is raised when the transaction documentation submitted by the merchant — typically a receipt or sales draft — cannot be read clearly enough to verify the transaction details. This is a documentation quality dispute, not a fraud allegation. It most commonly arises when a merchant submits a blurry scan, faded thermal receipt, or low-resolution image in response to a retrieval request or chargeback.
LT is entirely preventable. The chargeback is not about the transaction itself — it is about the quality of the documentation you provided. High-resolution scanning and digital receipt archives eliminate this code entirely.
Common Trigger Scenarios
- Faded thermal receipt submitted. Thermal paper fades over time. A receipt stored for weeks or months may be completely unreadable by the time a dispute arrives.
- Low-resolution scan submitted. A receipt scanned at 72 DPI or photographed with a phone camera in poor lighting may fail Discover's legibility standards.
- Handwritten receipt not legible. Handwritten sales slips with poor penmanship or faded ink are a common cause of LT.
- Wrong document submitted. An entirely unrelated document was submitted in place of the transaction receipt.
Evidence You Will Need
- High-resolution rescanned receipt — if the original is still legible, rescan at 300 DPI or higher
- Digital transaction record — POS system records that show the same transaction data in a readable format
- Authorization record — the authorization confirmation from the payment processor showing transaction details
Get the Complete Defense Playbook
The Processing Error Defense Guide covers the full representment strategy, evidence packaging, and response language for Discover LT and related codes.
Get the complete defense playbook →How Merchants Lose This Dispute
- Submitting blurry phone photos of receipts. Phone photos taken under poor lighting conditions rarely meet legibility standards. Use a flatbed scanner.
- Relying solely on thermal paper archives. Thermal receipts fade. Digital backups or re-printing to plain paper before archiving prevents LT.
- Missing the response window. LT can often be resolved by resubmitting better documentation, but only if you respond within the 30-day window.
Response Framework Overview
- Rescan the original document at high resolution. If the physical receipt is still legible, rescan at minimum 300 DPI with good contrast.
- Pull the digital transaction record from your POS. Electronic records from your payment system are legible by definition and match the original transaction data.
- Submit the clearest available version promptly. The 30-day response window is short — prioritize documentation quality over speed.
Prevention Tips
- Archive receipts digitally at point of sale. Digital receipt systems eliminate the thermal fading problem entirely.
- Set scanning standards. If you scan paper receipts, require minimum 300 DPI and verify legibility before filing.
- Test your dispute submission portal. Submit a sample document to verify that your acquirer's portal is receiving files at acceptable resolution.
Frequently Asked Questions
What resolution should I scan receipts at to avoid LT?
Scan at a minimum of 300 DPI for black and white receipts. Color scans should be at least 200 DPI. Verify the file is legible on screen before submitting. PDF format is generally preferred over JPEG for document clarity.
Can I submit a reprinted copy instead of the original?
Yes. A reprint or digital record from your POS system that shows the same transaction details is acceptable if the original is illegible. Electronic records from your payment system are legible by definition and often stronger evidence than a faded paper receipt.