What Is a Certificate of Deposit (CD)?

Almost every explanation of a certificate of deposit starts by telling you it is a savings account with a fixed term. True, and useless. What matters is the trade, because it has two sides and most people only look at one.

You are selling access to your own money. The bank pays you a fixed rate for a fixed period, and in exchange it gets certainty the deposit will sit there. That is why CD rates can beat easy access rates, and everything else about the product follows from that single fact.

So the useful question is never "what rate does this CD pay". It is "what am I being paid for the lock, and what does breaking the lock cost me".

What you actually agree to

When you open a CD you fix four things at once: the amount, the term, the rate, and the exit terms.

The first three are on the front of the advert. The fourth one is where the money is won or lost, and it is in the disclosure. The Consumer Financial Protection Bureau makes the point directly, telling savers to compare the penalty for withdrawing before the end of the term when shopping around, not just the headline rate.

Penalties are usually expressed as a number of days of interest rather than a percentage of your balance. A one-year CD might carry a penalty of 90 days of interest, a five-year CD might carry 180 days or more. On short terms with big penalties, the penalty can eat more than everything you have earned so far, which is why the phrase "you can always break it" deserves a second look.

The other clause worth finding is what happens at maturity. In the US, CDs commonly renew themselves automatically into a new term unless you tell the bank otherwise within a short grace window after the maturity date, often around a week to ten days. Your disclosure states the exact number. Miss it and you can find yourself locked into another term at whatever rate the bank felt like offering, which is a bad way to lose a year.

The penalty math, on real numbers

Here is the calculation almost nobody runs, and it changes the answer surprisingly often.

Say you put 10,000 dollars into a three-year CD at 4.00 percent APY, with an early withdrawal penalty of 180 days of simple interest. Fourteen months in, you spot a new account paying 4.75 percent and you are tempted to jump.

• Interest earned so far: 10,000 at 4.00 percent for 14 months grows to about 10,468, so you are up roughly 468 dollars.
• The penalty: 180 days of simple interest on 10,000 at 4.00 percent is about 197 dollars.
• Walk away with: about 10,271.

Now compare the two futures over the remaining 22 months. Stay put and your 10,468 compounds at 4.00 percent to roughly 11,249. Break out and your 10,271 compounds at 4.75 percent to roughly 11,183. Staying wins by about 66 dollars, even though the new rate is three quarters of a point higher.

Run the break-even and you need somewhere around 5.1 percent on the new account to make the move worthwhile at that point in the term. That is a much higher bar than most people assume when they see a shiny rate.

Two lessons fall out of it. The penalty is charged on principal while your gain is only on the rate difference, so the penalty is almost always the bigger number early on. And the closer you are to maturity, the less a rate switch can possibly earn you, because there is less time left to earn it in. If you want to sanity check any of this yourself, the how APY works explainer covers the compounding formula behind these figures.

Laddering, which is the actual technique

The real objection to CDs is not the rate. It is that locking everything away for five years is unusable if life happens in year two. A ladder fixes that without giving up the long rates.

Split the money into equal slices with staggered maturities. With 25,000 dollars you might open five 5,000 dollar CDs at one, two, three, four and five year terms. Each year one matures, and you either spend it or roll it into a new five-year CD. After four years every rung is a five-year CD, so you are earning long-term rates while still having a chunk come free every twelve months.

The quiet benefit is that a ladder stops you having to forecast interest rates. If rates rise you are reinvesting a rung every year at the new higher level. If they fall you still hold rungs locked in at the old higher level. You do not need to be right about the direction, which is fortunate, because nobody is.

The same product, three different rulebooks

The concept travels. The consumer protections do not, and the differences are exactly the ones generic articles skip.

	United States	United Kingdom	Canada
Usual name	Certificate of deposit (CD)	Fixed rate bond or fixed term savings account	GIC or term deposit
Early access	Normally allowed, for a penalty stated in the disclosure	Frequently not allowed at all during the term	Depends entirely on redeemable versus non-redeemable
Deposit protection	FDIC, 250,000 dollars per depositor per insured bank per ownership category, with equivalent NCUA cover at credit unions	FSCS, 120,000 pounds per eligible person per firm since 1 December 2025	CDIC, 100,000 dollars per insured category at each member institution
Tax shelter available	IRA or similar retirement account	Cash ISA, which is where fixed rate deals are commonly held	TFSA, RRSP or FHSA

Three points deserve spelling out.

United States. FDIC cover is per depositor, per insured bank, per ownership category, which means large savers can legitimately hold more than 250,000 dollars in protected CDs by spreading across banks or ownership categories. On tax, the IRS treats CD interest as ordinary taxable interest, and banks issue Form 1099-INT once interest reaches ten dollars in a year. On a multi-year CD that can mean owing tax on money you cannot yet spend.

United Kingdom. The single biggest difference is liquidity: many fixed rate bonds contain no early exit at all, so the American instinct of "worst case I pay a penalty" simply does not apply. Protection is also higher than most people think, because the FSCS limit rose to 120,000 pounds per eligible person per firm on 1 December 2025, with qualifying temporary high balances protected up to 1.4 million pounds for six months. Watch the shared banking licence trap, where two brands you think of as separate banks share one limit. On tax, the Personal Savings Allowance covers 1,000 pounds of interest for basic rate taxpayers, 500 pounds for higher rate taxpayers and nothing for additional rate taxpayers, which is why higher earners tend to hold fixed rate deals inside a cash ISA instead.

Canada. Federally regulated institutions must disclose the key details of a GIC or term deposit in clear, simple language that is not misleading before they sell it to you, so ask for that summary and read the redemption line first. Non-redeemable is the default assumption you should make unless the paperwork says otherwise. GIC interest is taxed as ordinary income at your marginal rate when held outside a registered plan, and on multi-year GICs it is generally reported on an annual accrual basis rather than only at maturity, so expect T5 slips before the money arrives.

When a CD is the wrong tool

CDs get sold as a safe default, and safety is not the same as suitability.

Do not put your emergency fund in one. A fund that costs you a penalty to reach has stopped doing its job. Keep that money in an easy access account, and if you are unsure which account type belongs where, the difference between checking and savings accounts is the right starting point.

Do not use one for money with an uncertain date. A house deposit that might be needed in nine months or in eighteen is a bad fit for a rigid twelve-month lock, especially in the UK where you may not be able to break it at all.

And do not treat one as a growth vehicle. A guaranteed nominal rate is not a guaranteed real return, because inflation is subtracted afterwards. For money you will not need for a decade, the conversation is about investing, not deposit products.

Where a CD does earn its place is money with a known date and a known job: tax set aside for a bill you can see coming, a deposit for something already contracted, cash you want protected from your own impulse to spend it.

One last piece of housekeeping. Check what the account the interest pays into charges you, because there is no point earning an extra quarter point and handing it back in monthly fees. Avoiding bank fees is a faster win than most rate chasing.

The bottom line

A certificate of deposit is a straightforward deal: you promise not to touch the money, and the bank promises the rate. Judge it by whether the premium over an easy access account is genuinely worth losing access, read the early withdrawal clause before the headline rate, and run the penalty math before you break one, because the arithmetic usually says stay. If you want the long rates without the long lock, build a ladder. And whichever country you are in, check the protection limit and the tax wrapper first, since both are worth more than the fraction of a percent most people spend their time hunting.