Minimum spend and bonus caps, explained
Most high-earning cards have two catches: you must spend a minimum each month to unlock the bonus, and the bonus stops after a cap.
Minimum spend
A card might pay 6% on dining, but only in months you spend S$800 or more in total. Miss it by a dollar and everything drops to the base rate, often 0.2% to 0.3%. Some cards check every month in a quarter (UOB One, HSBC Live+): one short month and the whole quarter's bonus is gone.
Caps
Bonuses are usually capped by cashback (for example, S$80 a month) or by spend (for example, the first S$1,000 a month). Spend beyond the cap earns the base rate. A 6% card capped at S$80 stops being a 6% card after S$1,333 in that category.
Per-transaction rounding
Many miles cards award points per S$5 per transaction. A S$9.90 coffee and cake earns as if it were S$5. Small purchases suit cashback cards better.