Because the Amex Platinum is a charge card with "No Preset Spending Limit," your spending power is dynamic and based on your history. To increase it in 2026, the best method is to consistently spend and pay off your balance in full every month. Amex’s internal algorithms look for a pattern of "responsible growth." If you have a large upcoming purchase, use the "Check Spending Power" tool in the Amex app; entering the amount there and getting a "Success" message essentially "pre-approves" that transaction and signals to Amex that you are expanding your spending. A supportive peer tip: don't use this tool too many times in one day, as it can trigger a manual review. If you need a permanent boost, you can also call customer service to update your annual income in your profile, as a higher income often leads to an automatic expansion of your internal "shadow limit."