Accounting errors don't always become apparent right away. In many cases, they accumulate quietly until they result in overpaid taxes, cash shortfalls, fines, tax problems, and difficulties in decision-making.
With the increase in electronic data matching, inconsistencies between invoices, bank transactions, payroll records, tax returns, and accounting records can be identified more easily by tax authorities.
In addition, 2026 marks an important milestone in the consumption tax reform, with the implementation of obligations related to the CBS and the IBS. This increases the need to review tax processes, systems, and documents.
Here are ten accounting mistakes your company needs to avoid in order to grow safely.
1. Mixing the company's finances with personal expenses
Mixing company funds with the partners' personal finances is one of the most common mistakes in business management.
This happens when personal expenses are paid directly from the business account or when partners withdraw funds without any record or planning.
This practice makes it difficult to determine the company’s true results and can cause problems with accounting, cash flow, and verifying the source of financial transactions.
To avoid this mistake, the company should:
maintain a bank account exclusively for the business;
correctly set the partners' pro-labore;
record withdrawals and distributions of profits;
keep receipts for expenses;
Perform bank reconciliations on a regular basis.
2. Remaining in the wrong tax bracket
The choice of tax regime should not be based solely on revenue or on the assumption that a particular regime is always more cost-effective.
Depending on the business activity, profit margin, payroll, expenses, and available tax credits, a company may see very different results under the Simples Nacional, Presumed Profit, or Actual Profit tax regimes.
Staying in an inappropriate tax regime can cause the company to pay more taxes than it should or to assume obligations that are incompatible with its structure.
Tax planning should take the following into account:
current and projected revenue;
type of work performed;
profit margin;
deductible costs and expenses;
payroll;
interstate operations;
the possibility of applying credits;
changes resulting from the tax reform.
This analysis must be conducted in advance, because the choice of tax regime typically takes effect for the entire calendar year.
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3. Issuing invoices with incorrect information
It's not enough to simply issue the invoice. The information included must also be accurate.
Errors in the service code, tax classification, CFOP, NCM, taxation, withholdings, or customer data may result in incorrect payments and discrepancies in ancillary obligations.
An incorrectly issued invoice can result in:
undue payment of taxes;
incorrect use of credits;
rejection of the document;
need for cancellation or correction;
discrepancies in SPED;
problems with customers and suppliers;
risk of inspection.
The company must keep its records of products, services, customers, and suppliers up to date, and periodically review the settings of the invoicing system.
4. Failure to adapt the systems to the tax reform
The consumption tax reform is already affecting companies' day-to-day operations.
The year 2026 marks the start of the testing period for the CBS and the IBS. According to the Federal Revenue Service’s guidelines, the trial tax rate is 0.9% for the CBS and 0.1% for the IBS, subject to the rules applicable to the transition period. citeturn835750search11
Effective August 3, 2026, companies under the regular tax regime must fill out the fields related to the IBS and CBS in electronic tax documents covered by the new rules. citeturn835750search5
To learn about the concepts and impacts of these new taxes, read the CLM Controller guide on CBS and IBS in Corporate Taxation.
The company may also consult:
o Text of Supplementary Law No. 214/2025 in the Federal Senate;
CLM's updated content on Tax reform.
Therefore, it is not enough to simply keep track of changes in tax rates. Companies also need to review:
management systems and ERPs;
issuing invoices;
product and service registry;
tax classification of transactions;
commercial contracts;
price formation;
integration between finance and accounting;
purchasing and sales processes.
Putting off this adjustment until later can result in rejected returns, incorrect data, errors in the calculation, and difficulties in claiming tax credits.
Another important point is understanding how tax credits work. CLM explains this topic in its article on the non-cumulative system of the IBS and CBS.
The preparation should involve the accounting, tax, financial, legal, commercial, and technology departments.
5. Failure to perform bank reconciliation
Bank reconciliation involves comparing the transactions on the bank statement with the records in the financial and accounting systems.
Without this process, duplicate payments, fees, unidentified receipts, transfers, and incorrect entries can remain hidden for months.
The lack of reconciliation also causes the financial statements to show figures that do not reflect the company's actual financial situation.
Ideally, the reconciliation should be performed regularly, verifying:
inputs and outputs;
accounts payable;
accounts receivable;
bank fees;
transfers between accounts;
tax payments;
card payments;
loans and financing.
In addition to reconciliation, it’s important to monitor cash flow, working capital, and financial projections. Here’s how a financial management integrated with corporate strategy.
A small discrepancy that goes unnoticed today can turn into a huge headache at the end of the fiscal year.
6. Submit ancillary obligations containing inconsistent information
Companies file various tax returns and accounting records throughout the year. Much of this information is cross-checked electronically.
Data submitted through SPED, DCTFWeb, EFD-Reinf, eSocial, and other reporting requirements must be consistent with invoices, payroll records, financial records, and accounting records.
As of January 2025, the liabilities previously reported on the DCTF PGD must now be reported on the monthly DCTFWeb via the Tax Entry Module (MIT). citeturn835750search15
To view manuals, frequently asked questions, and official guidelines, visit the DCTFWeb of the Federal Revenue Service.
Companies can also consult the eSocial's official website and SPED National Portal.
Among the most common mistakes are:
divergent values;
omitted recipes;
incorrect withholdings;
outdated records;
duplicate entries;
inconsistent employment information;
inappropriate classification of transactions;
delay in filing tax returns.
These errors can result in fines, tax disputes, obstacles to issuing certificates, and the need for corrections.
7. Confusing profit with cash on hand
A company may report a net income and still have trouble paying its bills.
This is because profit and cash flow represent different types of information.
A sale on credit can increase a company’s net income, even though the money has not yet been received. Similarly, the purchase of equipment, loan payments, and other disbursements can reduce cash on hand without representing an immediate expense on the income statement.
To avoid making the wrong decisions, the company should monitor:
available balance;
accounts payable;
accounts receivable;
default;
working capital requirements;
average collection period;
average payment term;
cash flow projection.
To learn more about this topic, check out the content on financial planning and working capital.
Distributing profits without assessing financial availability can jeopardize salaries, suppliers, taxes, and investments.
8. Failure to properly store tax documents and records
Document management is no longer just about storing boxes of paper.
Today, much of the accounting and tax information exists in digital format. This includes XML files for invoices, contracts, supporting documents, bank statements, receipts, reports, payroll records, and files submitted to government agencies.
O Public Digital Bookkeeping System It brings together various tax and accounting records used in dealings between companies and tax authorities.
A lack of documents can make it difficult to:
proof of expenses;
the use of credits;
the defense during an inspection;
the reconciliation of accounting records;
the conduct of audits;
securing financing;
the sale or reorganization of the company.
The company must establish a document retention policy that includes access controls, organization, backups, and retention periods defined for each type of document.
Complete Guide to
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9. Ignoring accounting and financial indicators
Accounting isn't just for calculating taxes and filing tax returns.
Financial statements provide important information about the financial health of a business. Ignoring them means managing the company without a clear understanding of its risks and results.
Some indicators that should be monitored are:
profit margin;
profitability;
indebtedness;
liquidity;
working capital;
break-even point;
trends in expenditures;
default;
profitability by product or service.
This data helps identify waste, evaluate investments, negotiate with banks, review prices, and plan for growth.
The Cash Flow Statement also helps you understand where funds come from and where they go. Learn more in the article on Cash Flow Statement and Business Management.
When accounting is updated only at the end of the year, it loses much of its strategic value.
10. Treating accounting merely as a bureaucratic obligation
The biggest mistake is to consult an accountant only when a problem arises, a fine is issued, or an audit takes place.
Strategic accounting should guide the company throughout the year, supporting decisions related to hiring, investments, profit distribution, the addition of new partners, the opening of branches, and tax changes.
This monitoring allows for:
identify risks in advance;
reduce process failures;
assess the tax impact of decisions;
improve financial control;
prepare the company for inspections;
to provide reliable information to managers and investors;
find legitimate opportunities for tax savings.
To understand how this initiative can support managers, read CLM's content on Strategic Accounting and Business Competitiveness.
