Determine the value of an antique postcard by first examining the card for damage and identifying markers. Look up the card to find its price or identification number using an antique postcard price guide. Another way to determine the value of an antique postcard is to get a professional appraisal.
The value of an antique postcard depends on its age, condition, topic and rarity. Postcards from the late 1800s and early 1900s are very old, and therefore more desirable. Tears, creases, ink marks or other stains can decrease the value of an antique postcard, while rare topics such as Halloween or special events increase a postcard's value.