What is the youngest age at which a person can apply for a PNB credit card? Are there specific credit cards available for individuals under 21 years old, such as student or add-on cards? What is the oldest age at which a person can apply for a PNB credit card? Do senior citizens have any restrictions when applying for a credit card? Are different age criteria applicable for salaried and self-employed individuals? Do applicants under a certain age need a co-applicant or guarantor? What is the minimum age requirement for an add-on (supplementary) credit cardholder? Can minors (below 18 years) get a PNB credit card as an add-on under a parent or guardian’s account?