COA expiry and retest calculator
A lab report is only as good as its date. Enter the test date and your shelf-life rule to see when the report expires and the last day to send a retest sample so the result is back in time.
Enter the test date from the lab report to see the dates.
How the dates are worked out
- Expiry is the test date plus your shelf life in months.
- The send-by date is expiry, minus the lab's usual turnaround, minus a safety buffer for shipping and delays.
Many suppliers use a shelf life of 12 to 24 months for reports. Pick one rule and apply it to every batch. More on building a library buyers trust: how to build a COA library.
Never sell from an expired report
Purity holds a batch automatically when its lab report expires, and reminds you when a retest is due.