Deferred Interest vs 0% Intro APR: How the Paid-in-Full Rule Works

Published by the Modern Lending Solutions editorial team. Last reviewed: October 30, 2026.

Short answer: with a true 0% intro APR, no interest is added during the promotional period, and interest on any balance left starts only when the period ends. With a deferred interest offer, interest builds up in the background; if you do not pay the whole promotional balance by the end date, that interest is charged back to the date of the purchase. The CFPB’s tip: “Look for the ‘if.’” This is general information, not legal or financial advice.

How to tell them apart

The CFPB says: “Zero interest offers use language like ‘0% intro APR on purchases for 12 months.’ Deferred interest offers use language like ‘No interest if paid in full within 12 months.’” With a zero percent offer, if a balance is left when the period is over, “you will start to pay interest on that remaining balance only from the date the promotional period ends”. With deferred interest, if you do not pay off the entire promotional balance, “then interest going back to the date of the purchase will be added on top of the remaining balance” (CFPB blog, June 8, 2017, read October 30, 2026; this archived post may be out of date).

	0% intro APR	Deferred interest
Example wording (CFPB)	“0% intro APR for 12 months”	“No interest if paid in full in 12 months”
Interest during the period	None	Builds up, but is not charged yet
Balance left at the end	Interest starts from the end date	All interest back to the purchase date is charged
Main rule	12 CFR 1026.55(b)(1)	12 CFR 1026.16(h), 1026.7(b)(14), 1026.53(b)(1)

What the law calls deferred interest

Regulation Z defines deferred interest as “finance charges, accrued on balances or transactions, that a consumer is not obligated to pay or that will be waived or refunded to a consumer if those balances or transactions are paid in full by a specified date”, and the time until that date is the “deferred interest period” (12 CFR 1026.16(h)(2), eCFR, text up to date as of October 28, 2026, read October 30, 2026).

What a deferred interest ad must say

Under 1026.16(h)(3) and (4), an advertisement for a deferred interest offer on an open-end plan must:

Give the deferred interest period clearly and conspicuously.
If it says “no interest” or something similar, also say “if paid in full”, before the period is given.
In a written or electronic ad, put the period and “if paid in full” right next to each “no interest”, “no payments”, “deferred interest”, “same as cash” or similar term.
Say that interest will be charged from the date of the purchase if the balance is not paid in full within the period.
If it applies, say that interest will be charged from the date of the purchase if the account is in default before the period ends.

So “if paid in full” in an offer is the sign that it is deferred interest.

The pay-by date on every statement

For a balance in a deferred interest program, each periodic statement during the period must show, on the front of a page, the date by which the balance must be paid in full to avoid the interest (12 CFR 1026.7(b)(14), eCFR). For the rest of the statement, see credit card statement explained.

How your extra payments are applied

When you pay more than the minimum, the card issuer must apply the extra to the balance with the highest APR first (12 CFR 1026.53(a)); see credit card payment allocation. For a deferred interest balance, there is a special rule: “during the two billing cycles immediately preceding expiration of the specified period, the excess amount must be allocated first to the balance subject to the deferred interest or similar program” (12 CFR 1026.53(b)(1)(i), eCFR). The issuer may also, at its option, apply the extra as you ask (1026.53(b)(1)(ii)). If you have other purchases on the same card, ask the issuer to send your extra payments to the promotional balance well before the last two cycles.

The true 0% intro APR

A card issuer may raise a rate when a promotional period of six months or longer ends only if, before the period began, it told you in writing, clearly and conspicuously, how long the period lasts and what rate applies after it (12 CFR 1026.55(b)(1)(i), eCFR). For a 0% offer on a balance you move from another card, see balance transfer card vs personal loan.

Back-charged interest, only for the math

This example is only for the math. The $1,200.00 purchase, the 12-month period and the $90.00 monthly payment are example figures. The rate is the Federal Reserve’s August 2026 average of 22.36% on credit card accounts assessed interest (G.19); your card’s rate may differ. Interest is figured simply, each month on the balance before that month’s payment.

You pay $90.00 x 12 = $1,080.00, so $120.00 of the purchase is left at the end of the period.

Offer	What you owe when the period ends
0% intro APR	$120.00 (interest on it starts from the end date)
Deferred interest, not paid in full	$120.00 + $157.63 back-charged interest = $277.63
Deferred interest, paid in full in time	Nothing more: $1,200.00 / 12 = $100.00 a month would have cleared it

Your issuer’s own balance method may give a different figure. For costs that come with offers like this, see dental costs options and a personal loan for orthodontics and dental implants. For a plan with set installments instead, see buy now, pay later vs a personal loan.

Questions to ask before you sign up

Is this a 0% intro APR, or is it no interest if paid in full?
What is the exact date the promotional balance must be paid by, and what rate applies after?
If I miss a payment, does the promotion end early and is interest charged back to the purchase date?
What monthly payment pays the whole balance off before the end date?
If I make other purchases on this card, how will my payments be applied?

Checklist

Look for “if paid in full” in the offer.
Divide the balance by the months in the period, and pay at least that each month.
Find the pay-by date on each statement.
Avoid adding other purchases to a card with a deferred interest balance, or ask how payments will be applied.
Plan to pay the balance in full before the end date, not on it.

Start your loan request How our service works

Sources

Disclosure: Modern Lending Solutions is not a lender, loan broker or agent for any lender or loan broker, and does not make credit decisions. Any compensation we receive is paid by participating lenders, only for advertising services. This guide is general information, not financial or legal advice.

Deferred Interest vs a 0% Intro APR: How to Tell Them Apart