20 000 Rials Large portrait

Iran's large-portrait series was introduced as part of a broader effort to modernize security features after years of successful counterfeiting operations targeting the earlier issues. The 20,000 Rial denomination, when it appeared in this format, was a significant face value in everyday circulation — by the mid-2000s, inflation had thoroughly eroded smaller notes into near-irrelevance for most transactions.

The watermark remains the primary security element, which reflects how relatively modest the anti-counterfeiting investment was for this series compared to contemporaneous issues from neighboring central banks. Cotton substrate is standard for Iranian notes of this period.