CDB investment in Brazil: a comprehensive guide

CDB (Certificado de Depósito Bancário) is a private fixed-income security that represents a time deposit made by an individual or legal entity. In practice, investing in a CDB means lending money to a qualifying financial institution, which promises to repay the principal at a future date plus the agreed interest.

This guide explains CDBs without recommending specific products or guaranteeing returns. Information is drawn from official sources including B3, the Banco Central do Brasil (BCB), CVM, and the FGC.

TL;DR

• A CDB is a bank time deposit: you lend money to a financial institution in exchange for a fixed or index-linked return, with the principal repaid at maturity.
• Returns can be fixed-rate or post-fixed against the CDI (B3-published interbank DI rate); the CDI is a benchmark, not a guaranteed yield.
• The FGC guarantees up to R$ 250,000 per CPF/CNPJ per institution or financial conglomerate (R$ 1 million aggregate cap in four years), but credit risk does not vanish above that threshold.
• Income tax is regressive (22.5%–15% by holding period); IOF may apply if redeemed within 30 days.
• Liquidity and maturity vary per contract (daily liquidity, market liquidity, or no early redemption) — check the issuance sheet, not the platform's marketing.

What is a CDB?

A CDB is a bank deposit certificate issued to raise funds for the financial institution. The security is created through an investment agreement that defines maturity, liquidity, and remuneration. Returns can be:

• Fixed rate: A predetermined interest percentage expressed as annual per annum (a.a.)
• Post-fixed rate: Linked to a benchmark, typically the CDI (Certificado de Depósito Interfinanceiro)

The investor receives the agreed remuneration based on the chosen rate type and holds the certificate until maturity or early redemption (if allowed). For background on where CDBs sit in the broader Brazilian fixed-income landscape, see what is fixed income in Brazil.

Understanding CDI as the reference rate

The CDI is an interbank deposit certificate used in very short-term operations between financial institutions. The term "CDI" is popularly used to refer to the associated interest rate, officially called Taxa DI.

The DI rate is calculated and published by B3 based on the weighted average of interbank deposit operations prefixed with one business day maturity, conducted between institutions of different groups. B3 DI rate methodology

Why CDI serves as a benchmark

The DI rate is the primary benchmark for various fixed-income investments:

• CDBs;
• LCIs and LCAs;
• fixed-income funds and DI funds;
• debentures and other private title securities;
• DI futures contracts.

A CDB paying 100% of the CDI tracks the accumulated DI rate over the period; a CDB paying 120% of the CDI offers returns 20% above this reference, per the product conditions. B3 DI rate methodology

Fixed vs. post-fixed rates

Fixed-rate CDBs guarantee a predetermined interest percentage regardless of market fluctuations. For example, a CDB with a 10% fixed rate will pay approximately 10% per year, even if the CDI falls to 4% B3 CDB definition.

Post-fixed (variable) CDBs have their returns tied to a benchmark. The most common structure is CDI plus a spread:

Fixed rates protect against falling benchmarks but may offer lower returns when rates rise. Post-fixed rates allow higher returns in rising-rate environments but expose investors to rate volatility.

Maturity and liquidity structures

Maturity

Maturity (vencimento) is the contractual date when the issuer must return the principal plus agreed remuneration. CDBs can range from 30 days to over 10 years B3 CDB liquidity guidance.

Liquidity

Liquidity determines how and when an investor can redeem before maturity:

• Liquidez diária (daily liquidity): Can be redeemed each business day directly with the issuing bank according to the title's terms
• Liquidez a mercado (market liquidity): Can only be redeemed through sale in the secondary market, with price subject to market conditions
• Post-vencimento (after maturity): No early redemption; funds released only at maturity

Important distinction: Daily liquidity does not equal secondary market trading. Daily liquidity allows direct redemption with the issuer; secondary market involves selling to another investor. For context on how secondary market pricing works, see bond market in Brazil.

Credit risk of the issuer

What is issuer credit risk?

Investing in a CDB means lending money to the issuing financial institution. The primary risk is the issuer's credit risk: the possibility that the institution will not pay the principal and remuneration at maturity.

The Banco Central defines credit risk as the risk that the issuance or redemption commitment will not be honored as scheduled. BCB issuer risk guidance

Responsibility lies with the institution that issued the CDB, not necessarily the brokerage or digital bank where you purchased the product. The issuer's name and CNPJ (company registration number) appear on the investment confirmation and must be verified.

How to assess issuer risk

Before purchasing a CDB, check:

1. Exact issuer and CNPJ — Do not rely solely on the commercial brand or platform name
2. Central Bank authorization — Verify the institution in the official "Encontre uma instituição regulada/supervisionada pelo BC" service for registration data, corporate structure, available financial statements, and authorized operations BCB Encontre instituição
3. Financial conglomerate — Check whether you already hold other products issued by entities in the same group, since FGC limits apply per conglomerate
4. Financial indicators — When available, review net equity, profit/loss, capital adequacy, liquidity, default rates, and credit portfolio concentration
5. Credit ratings — Use as auxiliary information only; ratings can change and do not eliminate default risk
6. Offered remuneration — A CDB paying significantly above CDI typically reflects higher funding needs and may signal higher perceived risk; not proof of problems, but warrants additional analysis
7. Liquidity and maturity — CDBs without daily liquidity may require holding until maturity; contractual liquidity differs from credit risk

Regulatory oversight

For bank-issued CDBs, the primary regulator is the Banco Central do Brasil, not the CVM. The CVM states that CDB-related matters fall under Central Bank jurisdiction. The Central Bank also confirms that banks, finance companies, and other financial institutions may issue CDBs under applicable regulations. BCB FGC limits

FGC coverage limits

What is the FGC?

The Fundo Garantidor de Créditos (FGC) is a private, non-profit entity that protects depositors and investors against financial institution failures. Eligible CDBs fall under the FGC's ordinary guarantee. Learn more about the guarantee system at FGC coverage limits or in the FGC FAQ.

Current coverage limits (2024–2025)

The R$ 250,000 limit applies to principal plus accrued yields up to the intervention or liquidation date. Investing exactly R$ 250,000 may leave part of the interest uncovered. FGC FAQ

How the limits work

• Separate limits per institution: If you hold R$ 150,000 in a CDB at Bank A and R$ 150,000 in an LCI at Bank B (different conglomerates), both can be fully covered FGC FAQ
• Same conglomerate aggregation: Holdings in institutions belonging to the same financial group sum toward the single R$ 250,000 limit FGC FAQ
• CPF and CNPJ are independent: An individual's CPF limit and a company's CNPJ-root limit operate separately

Products normally covered

Savings accounts, current accounts, CDBs, RDBs, LCIs, LCAs, LCs, LHs, LCDs, and certain repurchase agreements. Products not covered under ordinary guarantee include: investment funds, Tesouro Direto, debentures, CRIs, CRAs, LIGs, financial bills, and capitalization titles. FGC FAQ

Does FGC eliminate risk?

No. FGC reduces but does not eliminate risk:

1. Amounts above the limit may not be fully recovered
2. Holdings in the same conglomerate aggregate
3. Operational delays may occur before guarantee payment
4. FGC is triggered only in intervention or liquidation scenarios
5. Uncovered or excess credits enter the legal liquidation process

Taxation on CDB returns

Income tax (Imposto de Renda)

CDB income tax applies only to the yield, not the principal. Rates follow a regressive table based on holding period: Receita Federal IR table 2025

The tax is automatically withheld by the financial institution at redemption or maturity. The taxable event occurs upon redemption, settlement, assignment, or other disposition. Receita Federal IR table 2025

Example: R$ 10,000 invested, R$ 1,000 gross yield after 200 days (20% rate). Tax = R$ 200; net yield = R$ 800; total redeemed = R$ 10,800 Receita Federal IR table 2025.

IOF (Imposto sobre Operações Financeiras)

If redeemed before 30 days, IOF applies on the yield in addition to income tax. The IOF rate starts at 96% on day 1 and declines daily to zero at day 30 Receita Federal IR table 2025.

Tax comparison table

Common errors and fixes

FAQ

What does CDB stand for?
Certificado de Depósito Bancário (Bank Deposit Certificate).

Is a CDB the same as a savings account (poupança)?
No. Savings accounts have fixed rules set by the Central Bank; CDBs have contractual terms defined by the issuing institution. Both are FGC-eligible.

Can I lose money in a CDB?
Yes. If the issuer fails and your total exposure (principal + yields) exceeds FGC limits, or if you redeem early with market liquidity and receive less than invested.

What happens if the bank fails?
The FGC pays covered amounts up to the limits, typically within weeks after intervention or liquidation decree.

Do I need to declare CDB earnings in my annual tax return?
Yes. Even with withholding at source, the income and tax paid must be reported in the annual IRPF/IRPJ declaration.

Can foreigners invest in CDBs?
Yes, through a local custody account and CPF/CNPJ. Non-resident tax rules may differ; consult a tax specialist.

What is the minimum investment for a CDB?
Varies by issuer and platform. Some accept R$ 1; others require R$ 1,000 or more.

How is the CDI rate calculated daily?
B3 calculates the weighted average of interbank one-day prefixed deposits between different groups, published on business days. B3 DI rate methodology

Sources