PAN Structure:
• 1st-3rd letter: Series (AAA-ZZZ)
• 4th letter: Taxpayer type (P=Person, C=Company, H=HUF, F=Firm, A=AOP, B=BOI, G=Govt, J=AJ, L=Local, T=Trust)
• 5th letter: First letter of surname/name
• 6th-9th: Sequence number (0001-9999)
• 10th letter: Check character