Navigating the complexities of business taxes can feel overwhelming, but understanding common pitfalls can help you stay compliant and financially secure.

You might qualify to deduct business mileage for personal vehicles and expenses related to a home office.

In this guide, we’ll highlight eight frequent and costly tax preparation mistakes—and how to avoid them.

1. Using the Wrong Forms

Your business’s legal structure dictates which tax documents you need to file.

Sole proprietors, partnerships, LLCs, S corporations, and C corporations all have different tax requirements. Some may require additional attachments, such as a Schedule C for solo entrepreneurs filing Form 1040. Beyond federal income taxes, you may also be responsible for state and local income taxes, property taxes, payroll taxes, sales taxes, excise taxes, and franchise taxes.

If you’re unsure, consulting an experienced accountant can help ensure you use the correct forms and meet all requirements.

2. Filing Late

Late filing and payment can lead to hefty penalties.

Tax deadlines vary depending on income taxes, estimated taxes, payroll taxes, and employee and contractor statements. These deadlines can change annually, and some differ based on your business entity type. Stay up to date by checking IRS.gov and state and local resources.

If you need more time, you can file an extension—but remember, any taxes owed must still be paid by the original due date.

3. Mixing Business and Personal Expenses

The IRS warns that mixing personal and business finances is a common audit trigger.

This issue is especially prevalent among solo entrepreneurs who use a single credit card for both purposes. Not only can this result in incorrect tax claims, but it may also lead to missed deductions and potential penalties. Additionally, commingling funds can weaken liability protections offered by LLCs or corporate structures.

To avoid this, maintain separate bank accounts and credit cards for business transactions and clearly document any accidental mix-ups or reimbursements.

4. Getting Behind on Estimated Payments

Most businesses, from major corporations to side hustles, are required to make quarterly estimated tax payments.

If you owe more than $1,000 in income tax at year-end, you may face penalties and interest charges. Frequent non-compliance can also increase your risk of an audit.

Be sure to track quarterly tax deadlines—especially since they differ for corporations versus other business entities—and allocate enough time to prepare.

5. Ignoring Financial Records

If tax season feels like a last-minute scramble, your financial recordkeeping might need attention.

Accurately reporting income and expenses can be difficult without regularly updated income statements and account reconciliations. Additionally, failing to retain receipts and invoices can make it impossible to substantiate deductions in the event of an audit.

Consider using accounting software to streamline bookkeeping and tax preparation. If feasible, hiring a professional bookkeeper can help ensure accurate financial tracking while you focus on business growth.

6. Entering Incorrect Information

Even minor clerical errors can lead to tax complications.

Something as simple as transposing numbers—entering “37” instead of “73”—could miscalculate your tax liability and require an amended return. While tax software helps reduce errors, double-checking your entries against your financial records is crucial.

For best results, work with an experienced tax professional. If handling your own taxes, be diligent in reviewing all numbers before filing.

7. Overlooking Deductions

The IRS allows deductions for business expenses that are “ordinary and necessary.” Knowing what qualifies can help you maximize tax savings.

Independent contractors may deduct business mileage and home office expenses, while business owners who entertain clients can claim meal deductions under the Tax Cuts and Jobs Act. Working with a tax expert ensures you take full advantage of available deductions while remaining compliant with IRS regulations.

8. Handling Taxes Alone

Entrepreneurs often prefer a hands-on approach, but expert guidance is invaluable when it comes to tax preparation.

Business tax filings are more intricate than personal returns, and mistakes can be costly. A knowledgeable accountant not only helps with accuracy but may also assume some liability for errors in your return.

For added security, seek referrals from business peers and consult the IRS Directory of Federal Tax Return Preparers with Credentials and Select Qualifications.

We’re Here to Help

For personalized guidance on streamlining your business tax preparation, reach out to your financial institution today.