Filing your tax return accurately and on time is the fastest way to receive your refund. Yet every year, thousands of taxpayers experience unnecessary delays due to avoidable errors. As the 2026 tax season begins, understanding these common tax filing mistakes can help you avoid frustration, processing delays, and potential IRS notices.
Below are the most frequent mistakes that delay the refunds — and how to prevent them:
1. Missing Health Insurance Information (Form 1095-A)
One of the most common errors involves taxpayers who purchased health insurance through the Health Insurance Marketplace but fail to properly enter information from Form 1095-A.
This form is required to reconcile advance premium tax credits. If it’s missing or entered incorrectly, the IRS cannot process the return, often resulting in delayed refunds or follow-up notices.
Why it matters: This is one of the leading reasons refunds are delayed early in tax season.
2. Incorrect Reporting of Estimated Tax Payments
Another major issue — and one of the single greatest errors seen on tax returns — is inaccurately reporting quarterly estimated tax payments.
This includes:
- Underreporting payments made
- Overreporting payments
- Forgetting payments made under a spouse’s name or SSN
These errors are especially common among self-employed individuals, business owners, and high- income taxpayers and often lead to refund delays or IRS adjustments.
Best practice:
Keep detailed records of all estimated payments and verify totals before filing.
3. Missing or Incomplete Income Reporting
Failing to report all income sources remains a frequent problem, particularly when taxpayers file early or handle their own returns.
Commonly missed income includes:
- 1099 income
- Gig or freelance earnings
- Interest, dividends, or investment income
Because the IRS receives copies of these forms directly, any mismatch can pause processing.
4. Filing Too Early Before All Documents Are Received
Many taxpayers rush to file as soon as tax season opens. However, filing before receiving all income statements often leads to amended returns — which can delay refunds for weeks or even months.
Tip: Filing early is beneficial only when your information is complete and accurate.
5. Incorrect Bank Account Information
Direct deposit is the fastest way to receive a refund, but incorrect routing or account numbers can cause deposits to fail or force the IRS to issue a paper check, delaying payment.
Always double-check banking details before submitting your return.
Common Mistakes Seen on Self-Prepared Returns
For taxpayers who prepare their own returns, certain issues come up repeatedly when accounting offices are asked to fix IRS notices or amend returns:
6. Math Errors
Calculation mistakes are very common on self-prepared returns and often trigger IRS adjustments or notices, delaying refunds.
7. Incorrect Credits and Deductions
Claiming credits or deductions incorrectly — or without meeting eligibility requirements — frequently leads to processing delays.
8. Filing Status and Dependent Errors
Errors involving filing status or dependents, including claiming ineligible dependents or choosing the wrong filing status, are another major reason returns are flagged for review.
How to Reduce Refund Delays in 2026
To help ensure faster processing:
- Don’t file until all tax documents are received
- Accurately report estimated tax payments
- Include Form 1095-A if Marketplace insurance was used
- File electronically and choose direct deposit
- Review credits, dependents, and filing status carefully
Professional review can often catch issues before filing and prevent delays altogether.
Final Thoughts
Most refund delays are not random — they’re caused by predictable, preventable mistakes. Paying close attention to health insurance reporting, estimated tax payments, and income accuracy can significantly improve processing times.
For taxpayers seeking professional support, the accounting firm David Oase, CPA provides personalized tax preparation and guidance to help clients file with ease and confidence.