Register now for FREE unlimited access to Reuters.com RegisterTo better prepare for defaults, AmEx built provisions of $778 million in the third quarter, compared with analysts' estimate of $604.1 million.
Still, the company expects to report full-year profit above its prior forecast of $9.25 to $9.65 per share.
The blending of work and leisure travel has also caught up, executives in the travel industry have said in recent months.
Strong growth in travel and entertainment in its international markets helped AmEx beat September-quarter profit estimates.
Revenue rose 24% to $13.6 billion, while expenses climbed 19% as AmEx had to spend heavily on customer rewards, compensation and marketing.