Answer-first explainers, comparisons, and market-context notes for decisions where rules of thumb are too blunt.
A 0% APR offer can reduce interest on eligible purchases during a promotional period, but it does not erase minimum payments, fees, expiration dates, or the need to understand whether the offer is true 0% APR or deferred interest. Read the agreement and model the payoff window before treating the offer as a cash-flow change.
Credit card payoff math is simpler than debt guilt makes it sound. The timeline changes based on four things: balance, APR, payment size, and how much cash the payment leaves for the rest of the month. A faster payoff usually saves a lot of interest, but only if the payment does not break everything else.
No, the 20% rule lowers risk, but it is not a hard cutoff. The right answer depends on the monthly payment, cash left after closing, mortgage insurance, and how long the money would stay tied up.