
Store Cards and "0% Financing"
"No interest if paid in full" is not the same sentence as "0% intro APR." The retroactive interest mechanism, drawn out, with the $120 shortfall that costs $270.
How checking accounts, credit cards, credit scores, and bank fees actually work in the US — explained line by line, with the official rules linked.

The five factors inside a FICO score, weighted and explained — payment history, utilization, age, new credit, and mix — plus the myths that refuse to die.

What actually happens when your account hits zero in 2026 — the opt-in rule that still protects you, the $5 cap that was repealed, and how fees now vary from $0 to $36.

What a security deposit actually does, how a secured card becomes an unsecured one, and the federal rules — deposit refunds, under-21 requirements, first-year fee caps — that shape your first card.

The exact sequence after a missed credit card payment — when the late fee hits, when credit bureaus find out, when the penalty APR can start, and what charge-off at 180 days really means.

How "free" checking accounts actually charge — the fee schedule line by line, the waiver conditions that do the work, and a worked example of a $259 year that was avoidable.