Store financing frequently advertises no interest for a fixed term. The arrangement behind that phrase is not the same as a promotional interest rate.
Interest accrues the entire time
Under deferred interest the charges accumulate from the day of purchase. They are held aside rather than waived, and they are recalculated at the card's ordinary rate.
If the balance reaches zero before the promotional period ends, the accumulated interest is cancelled and the customer pays only the purchase price.
If any balance remains, the full accrued amount is added at once. The trigger is the leftover balance, not its size.
Zero percent financing works differently
A true zero percent promotional rate charges no interest during the promotional window, and only the remaining balance accrues interest afterward.
Nothing accumulates in the background, so a customer who is late clearing the balance faces interest going forward rather than a retroactive charge.
The two offers are advertised with similar language, and distinguishing them requires reading the terms rather than the headline on the sign.
Minimum payments do not clear the balance
The required minimum payment on these accounts is generally calculated to leave a balance outstanding when the promotional term expires.
A customer paying exactly the minimum every month, on time, can still receive the full retroactive interest charge, which surprises people who believed they were compliant.
Clearing the balance requires dividing it by the number of months in the promotion and paying that figure, which exceeds the minimum in most cases.
Payment allocation complicates a mixed balance
When a card carries both promotional and standard balances, payment allocation rules determine which portion a payment reduces.
Federal rules direct amounts above the minimum toward the highest rate balance, with a specific provision applying near the end of a deferred interest period.
The practical consequence is that a customer carrying other purchases on the same card has less control over the promotional balance than they expect.
Where the disclosure actually lives
The governing terms appear in the account agreement and the promotional disclosure, not in the retail signage or the checkout conversation.
The critical items are the expiration date, the ordinary interest rate, and the exact language describing what happens to accrued interest at the deadline.
These offers are lawful and disclosed. The cost falls on customers who read the headline and assume the promotional term behaves like a waiver.