CDB: What It Is and How It Works in Practice
Have you heard about CDB and felt it’s something complicated, reserved for finance experts? The good news is that it’s one of the simplest and most accessible investments in the Brazilian market — understanding how it works can be an important step towards making more informed financial decisions.
The Certificate of Deposit (CDB) is a fixed-income security issued by banks. In practice, when you invest in a CDB, you are lending money to the issuing bank. In return, the bank commits to returning this amount in the future, with an agreed-upon remuneration. It’s a direct relationship: the bank needs resources, you lend, and you receive interest for it.
This article will explain how CDB works, its types, how it is taxed, the advantages and risks involved — and what you should consider before investing. The goal is to provide a solid foundation to understand this product without promises of quick wealth or personalized recommendations.
What is a CDB and How It Works
CDB is a resource-raising instrument used by banks of all sizes — from large institutions to medium banks and fintechs with banking licenses. When a bank issues a CDB, it registers the operation with B3 (the Brazilian stock exchange, which also operates the custody of fixed-income securities), and the investor gains a contractual right over that amount.
The operation is simple:
- You apply a minimum amount defined by the issuing bank.
- The bank sets the remuneration rate and the term of the security.
- At the end of the term (or in case of early liquidity, if provided), you receive the invested amount plus accumulated interest, already deducted from Income Tax.
The remuneration can be calculated in different ways, depending on the type of CDB — see the next section.
Types of CDB: Fixed, Floating, and Hybrid
There are three main types of CDB, and understanding the difference between them is essential to choose the one that makes the most sense for your financial situation.
Fixed CDB
In this type, the interest rate is set at the time of contracting and does not change. For example, the bank may offer a fixed annual rate. You know exactly how much you will receive at the end of the term — as long as you keep the investment until maturity.
Advantage: total predictability of return. Attention: if the economy’s interest rate rises after your application, you may miss the opportunity to earn more.
Floating CDB
It is the most common type in Brazil. The remuneration is linked to an index, usually the CDI (Interbank Deposit Certificate), which historically closely follows the Selic rate, the basic interest rate of the Brazilian economy set by the Central Bank.
Floating CDBs are usually expressed as a percentage of the CDI — for example, “100% of the CDI” or “110% of the CDI”. This means that your investment’s return follows the variations of this rate over time.
> How to check the current CDI: the DI rate (CDI) is disclosed daily by B3. You can check the updated value directly on B3’s official website (b3.com.br) or the Central Bank’s portal (bcb.gov.br).
Advantage: follows interest rate movements. Attention: if the Selic falls, the yield also falls.
Hybrid CDB (IPCA+)
In this case, the remuneration combines a fixed rate with the inflation variation measured by the IPCA (Broad Consumer Price Index). The logic is to ensure a real gain above inflation.
Advantage: protects your money’s purchasing power. Attention: if inflation is very low, the nominal return may be lower than a floating CDB in a high-interest scenario.
CDB Taxation: How Income Tax Works
CDB is an investment subject to Income Tax (IR), charged at the source at the time of redemption or maturity. The rate follows a regressive table: the longer you keep the investment, the lower the tax.
The current table, established by the Federal Revenue, works as follows:
| Investment Term | IR Rate |
|---|---|
| Up to 180 days | 22.5% |
| 181 to 360 days | 20% |
| 361 to 720 days | 17.5% |
| Above 720 days | 15% |
The tax applies only to the earnings, not the principal amount invested. Additionally, there is the IOF (Tax on Financial Operations), which is charged only on redemptions made in the first 30 days — and regressively, reaching zero from the 31st day.
> Important: the rates above are current according to Brazilian tax legislation. Always check for updates on the Federal Revenue website (gov.br/receitafederal) before investing.
FGC Protection: Understand What Is Covered
One of the factors that makes CDB popular among beginner investors is the coverage of the Credit Guarantee Fund (FGC). It is a private non-profit entity that protects deposits and investments in case of intervention, extrajudicial liquidation, or bankruptcy of the issuing bank.
The current FGC rules establish:
- Limit per CPF per institution: R$ 250,000
- Global limit per CPF: R$ 1,000,000, renewable every 4 years
This means that if the issuing bank of your CDB goes bankrupt and you have up to R$ 250,000 invested in that institution, the FGC covers the amount — principal and earnings.
> Attention: the limit is per institution, not per product. If you have R$ 200,000 in CDB and R$ 100,000 in savings in the same bank, only R$ 250,000 will be covered in total by that institution.
For amounts above this limit or for a diversified portfolio, it is worth distributing investments among different institutions. Check the updated rules directly on the FGC website (fgc.org.br).
Advantages and Disadvantages of CDB
Like any investment, CDB has positive and negative points. Evaluate both sides carefully.
Advantages
- Accessibility: many CDBs accept applications from low amounts, making them accessible to different profiles.
- Variety: you can find options with different terms, rates, and modalities.
- FGC Protection: within established limits, there is coverage in case of bank failure.
- Simplicity: it is a product easy to understand and track.
- Predictability (fixed): the return can be known in advance.
Disadvantages and Risks
- Credit risk: if the issuing bank fails and the amount exceeds the FGC limit, you may incur losses. Smaller banks may offer higher rates but also represent higher risk.
- Limited liquidity: many CDBs do not allow redemption before maturity or penalize early withdrawal. Always check liquidity before applying.
- Taxation: unlike some other fixed-income products (such as LCI and LCA), CDB is subject to IR on earnings.
- Market risk (fixed): in scenarios of rising interest rates, fixed CDBs may lose attractiveness compared to new issuances.
How to Invest in CDB: Step by Step
- Open an account with a broker or bank that offers CDBs. Many digital platforms and independent brokers allow you to compare options from different issuers.
- Define your goal: is it an emergency reserve (prefer CDBs with daily liquidity) or a medium/long-term investment?
- Compare the rates and terms available. Check if the issuer has FGC coverage and assess the institution’s credit risk.
- Check the liquidity: does the CDB have daily liquidity (withdrawal at any time) or only at maturity?
- Check the minimum amount required for application.
- Apply and track earnings through the chosen platform.
If you are building your financial organization for 2026, you can be inspired by the article Annual Financial Planning: Organize Your Finances in 2026 to better structure your goals before choosing where to invest.
And if you are self-employed or a freelancer and want to understand how to fit investments into your variable income routine, the guide Financial Education for Freelancers: Practical Guide can be an excellent complement to this article.
Conclusion: Is CDB for You?
CDB is a robust, transparent, and well-regulated fixed-income product suitable for different investor profiles — from beginners to those with a more structured portfolio. It offers simplicity, variety, and, within FGC limits, an important layer of protection.
But this does not mean it is the “best” product for everyone. The choice depends on your goal, available term, risk tolerance, and tax situation. Comparing CDB with other options — such as Treasury Direct, LCI, LCA, or fixed-income funds — is a valid and recommended exercise.
The most important thing is to understand what you are contracting before applying: what is the rate, what is the term, what is the liquidity, and who is the issuer. Information is the best starting point for any conscious financial decision.
This content is for educational and informational purposes only. It does not constitute investment advice, a financial product offer, or personalized consultancy. Each person has a unique financial situation. To make investment decisions suitable to your profile and goals, consult a certified professional or investment advisor duly registered with the Securities and Exchange Commission (CVM).
