For optimal storage, the longevity of flattened corrugated boxes relies on environmental factors, especially moisture levels. High humidity weakens adhesive bonds, while low humidity leads to drying, making the material brittle. Emphasizing "flattened," it maximizes space and minimizes edge damage. Under ideal conditions, we advise storing corrugated boxes for no more than 90 days. However, your discretion is crucial—if deterioration is noticed, erecting new boxes is recommended to uphold packaging integrity.