Every pilot, no matter how experienced, no matter how many thousands of hours logged, runs a pre-flight checklist before takeoff. It is not because they forgot how to fly. It is because the cost of skipping a step is too high to leave to memory.
Filing your tax return works exactly the same way. And most people skip the checklist entirely.
They gather what they remember, hand it off or type it in, and hit submit. Fully confident they got everything. Then, weeks or months later, they discover a missed 1099, an overlooked credit, or an income source they forgot existed. By that point, the options range from mildly inconvenient to genuinely expensive, depending on what was left behind.
This is not a judgment. Tax season is hectic. Documents arrive on staggered schedules. The entire experience is designed to feel like something you survive rather than something you master. But surviving it is not the same as maximizing it.
Let’s also get on thing straight… maximizing it starts before you ever think about Form 1040.
So consider this your pre-flight checklist. Not the kind that puts you to sleep. The kind that keeps you out of trouble and, more importantly, keeps more money in your pocket.
Step One: Run Down Every Piece of Income Documentation
The most common and costly pre-filing mistake is assuming you already have every income document you need. You probably do not.
Here is the issue: income documents arrive at different times. They come from different sources, in different formats, and poorly labeled. Not all of them come with a stamp that says “important tax document.”
Some documents arrive via email and are easy to find. Many of us have to gather PDFs buried in a portal login you have not checked since last February. Some do not arrive at all –> thanks USPS. Even though the income they represent absolutely happened and absolutely gets reported to the IRS.
The documents you want to track down fall into a few clear categories.
W-2s report the wages you or a family member earned while working for any company during the tax year. Even if you worked for just three weeks in January, that employer had to issue your W-2 by January 31.
Under 26 U.S.C. § 6051, employers who miss that deadline face penalties. But the IRS still expects you to report that income whether or not the W-2 landed in your mailbox.
1099s cover nearly everything else. A 1099-NEC captures independent contractor and freelance income. A 1099-MISC covers rent, prizes, attorney payments, and miscellaneous income. A 1099-K applies to payment platforms like PayPal, Venmo, and Stripe. A 1099-INT covers bank interest. A 1099-DIV covers dividends from investments. A 1099-R covers retirement distributions. A 1099-G covers unemployment benefits. The variety is significant, and the filing requirement applies to each one.
If you:
- ran a side business
- sold anything through a marketplace
- received any freelance payment
- or earned income in any non-traditional way
there is almost certainly a 1099 in circulation with your name on it. The question is whether you have it.
Do not guess. Log into every financial account, every bank, every brokerage, every payment platform, and every retirement account you own. Then, pull your year-end tax documents directly from the source. Cross-reference what you received against what you are reporting. A missing 1099 does not make the income invisible. It makes you the one who looks like they tried to hide it.
Step Two: Go Through Every Investment Account With Intention
Investment accounts deserve their own section.
Why? Because they produce more complexity per dollar than almost any other income source. Not to mention… most people either miss things entirely or misunderstand what they are looking at.
Start with your brokerage account statements. If you sold any stocks, mutual funds, ETFs, or other securities during the tax year. Those transactions generate a 1099-B, which captures your proceeds and, where available, your cost basis. That cost basis is critical. If it is wrong, your capital gain or loss is wrong. If you inherited securities, received stock as compensation, or transferred positions between accounts, the basis reporting may be incomplete or entirely missing. In these cases, the IRS will not assume the most favorable interpretation on your behalf.
Pay particular attention to wash sale rules under 26 U.S.C. § 1091. If you sold a security at a loss and bought a substantially identical security within 30 days before or after the sale, the IRS disallows that loss. Brokerages are required to track this within a single account, but they do not track it across multiple accounts. If you sold a losing position at Fidelity and bought the same thing at Schwab the following week, the wash sale still applies, and you are responsible for catching it.
Also review any cryptocurrency activity. The IRS has treated digital assets as property since 2014 under Notice 2014-21, which means every sale, trade, or disposal of crypto is a taxable event. Every single one. Many investors still do not know this. If you traded during the year, even small amounts, even just moving between coins, that activity needs to be reported, and you need documentation to support the cost basis of every position you disposed of.
Step Three: Review Every Credit and Deduction You Might Be Entitled To
This is where most of the money gets left behind. Not through fraud or aggressive positions. Through simple unawareness of what exists.
The tax code is not a single sheet of rules. It is a layered, constantly evolving document with credits and deductions buried throughout it, many of which the IRS does not advertise and many of which your software will not surface unless you know to look. Here are the areas I find most commonly missed.
The Child and Dependent Care Credit under 26 U.S.C. § 21 helps offset the cost of childcare or adult dependent care while you work. For tax year 2025, eligible expenses go up to $3,000 for one qualifying individual or $6,000 for two or more. The credit itself ranges from 20% to 35% of those expenses depending on your income. Many parents either do not know the credit exists, or assume they do not qualify because they used a Dependent Care FSA, when in reality you can claim both if you have qualifying expenses exceeding the FSA contribution.
The American Opportunity Tax Credit and the Lifetime Learning Credit, both governed by 26 U.S.C. § 25A, apply to qualified education expenses for you, your spouse, or your dependents. The AOTC provides up to $2,500 per eligible student, with up to $1,000 refundable, for the first four years of higher education. The LLC provides up to $2,000 per return for any level of education and any number of years. Both require Form 1098-T from the educational institution.
If you or a family member purchased health insurance through the Marketplace, the Premium Tax Credit under 26 U.S.C. § 36B needs to be reconciled against any advance credits already paid during the year. If your income was higher than estimated when you enrolled, you may owe some of that credit back.
On the other hand, if it was lower, you may be entitled to an additional credit. Either way, Form 8962 needs to be filed accurately or the IRS will flag the return.
The Energy Efficient Home Improvement Credit and the Residential Clean Energy Credit, both extended and modified by the Inflation Reduction Act, cover everything from heat pumps and insulation to solar panels and battery storage. Under 26 U.S.C. § 25C and § 25D, these credits can be substantial for homeowners who made qualifying upgrades in 2024. If you replaced windows, upgraded HVAC systems, or installed any form of renewable energy equipment, pull your receipts and confirm whether the products meet IRS energy standards.
If you are a business owner, and if you are reading this there is a good chance you are, the number of potentially missed deductions expands considerably. Home office deductions, business use of a vehicle, health insurance premiums, retirement contributions, Section 179 expensing, and the qualified business income deduction under 26 U.S.C. § 199A are all legitimately available, and all legitimately missed at alarming rates. I wrote at length about entity structure and how it affects your access to some of these deductions in this piece on tax strategy and entity structure. The interplay between your structure and your deductions is not something to figure out the night before the deadline.
Filing a return without confirming your credits is like leaving a gift card on the counter. The value is there. You just forgot to use it.
If you are approaching the deadline and feel uncertain about whether you have reviewed everything thoroughly, filing an extension is not defeat. As I explained in this article on extensions, deductions, and deadlines, an extension buys time to get it right, and getting it right is always worth it. What an extension does not do is extend your obligation to pay. Any tax owed is still due by April 15, even if the return itself comes later.
Step Four: Make Sure Everything Matches
This step trips up more people than you might expect. Tax returns get flagged not because someone made something up, but because what they submitted does not match what the IRS already received from third parties.
Every bank, employer, brokerage, and payment platform that issued you a tax document also sent a copy directly to the IRS. The agency uses an automated process called document matching to compare what was reported to them against what you reported on your return. When those numbers do not align, the IRS sends a notice. Usually CP2000, which proposes additional tax, interest, and sometimes penalties.
So before you submit, verify that every number on your return matches the source documents exactly. Not approximately. Exactly. If your 1099-NEC says $47,312, your return should not say $47,000. Small discrepancies are exactly the kind of thing that generates unnecessary correspondence, the kind that takes months to resolve and achieves nothing except stress.
Also check that your Social Security numbers, routing numbers, and account numbers are correct on the return. A transposed digit in a bank account number does not just delay a refund. In some cases, it sends the refund to the wrong account entirely, and recovering it becomes a months-long process that involves filing affidavits with the IRS and hoping the receiving bank cooperates. Check twice. It is free.
Step Five: Do Not Forget What Might Have Changed Since Last Year
The tax landscape for 2025 is not identical to 2024, and it is not identical to 2023. Thresholds change, credits phase in and out, rules get modified by legislation, and life circumstances shift in ways that affect your tax profile.
Retirement contribution limits for 2025 increased. Traditional and Roth IRA limits rose to $7,000, or $8,000 for those 50 and over. 401(k) limits rose to $23,500 for employee contributions under the SECURE 2.0 Act, with a special catch-up contribution of $11,250 available for those aged 60 through 63. If you did not max out and your income allows it, IRA contributions for 2025 can still be made through April 15, 2026. That is money that directly reduces your taxable income, or in the case of a Roth, builds entirely tax-free for your future. My articles on the SEP-IRA playbook and Solo 401(k) strategy walk through how business owners can use these vehicles to their full advantage.
Also consider: did you get married or divorced? Have children? Buy or sell a home? Start a business? Close one? Change states? Each of those events affects your filing status, your deductions, and potentially your rate. A return that accurately reflected your life two years ago may not accurately reflect it today. That is not a reason to panic. It is a reason to pause and think before you file.
The Checklist Is the Strategy
Most people think tax strategy happens in October, during year-end planning conversations. And it does. But tax accuracy, which is the foundation on which strategy sits, happens right now, in these final weeks before the deadline.
A missed document can trigger a notice. A missed credit means you unknowingly gave money to the Treasury. A mismatched number can trigger weeks of back-and-forth with an agency that doesn’t respond quickly. None of these outcomes are inevitable. They are the result of skipping the pre-flight check.
As I mentioned in a recent article on amended returns, there is always the option to go back and fix a return. But the three-year window on refund claims means that option is not unlimited, and the process of amending costs time, energy, and in some cases professional fees that a thorough pre-filing review would have avoided entirely.
The people I see get the most out of tax season are not necessarily the ones with the most complex situations. They are the ones who treat the return like what it actually is: a legal document with real financial consequences, worth reviewing with the same care they would give to a significant business contract. That habit of slowing down just enough to do it right the first time is the kind of thing that compounds quietly over years. And eventually, it starts to look a lot like financial progress.
Because it is.
Filing your taxes is not the finish line. It is where the next chapter of your financial story begins, and the more accurate the foundation, the better the story gets from here.
Welcome to the New Age of Accounting. Let’s begin.
P.S. If you found this article helpful, you’ll love my new book S-Corp Mastery: How Smart Business Owners Maximize Tax Savings & Build a Lasting Legacy. It’s now live and available in a sleek, easy-to-read PDF version. Grab your copy here
Chris is the Managing Partner at Weston Tax Associates, a best-selling author, and a renowned tax strategist. With over 20 years of expertise in tax and corporate finance, he simplifies complex tax concepts into actionable strategies that drive business growth. Originally from Sweden, he now lives in Florida with his wife and two sons.
