Credit card reward points expiry — what is the validity period?

Forex markup comparison: Amex = 3.5%, HDFC Infinia/Diners Black = 2.0%, Axis Atlas = 3.5% but with milestone fee waivers, ICICI Emeralde = 3.5%, Standard Chartered = 3.5%. If you travel more than twice a year, the math favours Infinia or Diners Black.

On credit limit increase: most banks auto-review every 6 months. If you use 30-70% of the limit and pay in full, you'll get an automatic increase. Don't call and ask for it explicitly — banks take it as a sign of credit hunger and sometimes lower the limit instead.