Tax Planning 101: How to Prepare for Tax Season Year-Round

Tax planning is the set of decisions you make before December 31 that change what you owe; tax preparation just records what already happened. In the 2026 filing season, the average federal refund was $3,571, up nearly 11% from the year before. Most people treat that as a win. In reality, it’s more like a zero-interest, sixteen-month loan you’ve made to the federal government. Shift how you think about taxes, and a clear distinction appears: tax preparation vs. tax planning. Let’s discuss the difference and what it could mean for your bank account.

Tax preparation is recording what already happened: gathering your W-2s, filling out a 1040, and filing by the deadline. Tax planning is different in that it’s how we change what happens through the decisions we make before the end of the year. These decisions determine what you owe before you ever open a tax form. Your adjusted gross income (AGI), which is your total income minus specific above-the-line deductions, is the number most of those decisions are trying to move. This is the lever that determines your tax bracket, your deduction eligibility, and a long list of downstream credits (e.g. the Saver’s Credit, Child Tax Credit, ACA premium tax credit).

Tax season isn’t decided in April. It’s decided in the other eleven months of the year. Let’s talk through the seasons of tax planning.

#Key takeaways

• Tax preparation is recording what already happened. Tax planning is changing what happens. Most available changes need to be made by December 31st.
• Assuming you’re already capturing any company-offered match, the single most effective move for most households is increasing your pre-tax contributions to a traditional 401(k), IRA, or HSA. Each dollar reduces your taxable income dollar-for-dollar. Roth contributions do not.
• For tax year 2026, the standard deduction is $16,100 for single filers and $32,200 for married filing jointly, and $24,150 for heads of household. More than 90% of taxpayers take the standard deduction.
• A large refund isn’t necessarily a win. The average 2026 refund was $3,571, and nearly 70% of filers received one. It’s the norm, and it means most people are overpaying all year.
• The SALT cap jumped to $40,400, which makes itemizing worth rechecking if you own a home in a high-tax state.
• The new deductions for tips, overtime, and car loan interest are scheduled to expire after 2028. They are worth using while available.
• Tax planning requires action. Tag your deductible expenses as they happen in Monarch.

#What is tax planning, and how is it different from tax preparation?

Most people conflate tax planning and tax preparation, which causes confusion and can cost them money.

The reason this distinction matters is that nearly every effective move has to happen before December 31st. This includes increasing a 401(k) contribution, harvesting a loss, and bunching multiple years of charitable giving into one as prime examples. By the time you’re sitting down in April with your documents, the tax year is already locked. Preparation can only tell you the results of the decisions you made.

This is why AGI is worth understanding early. Lowering it doesn’t just shrink your taxable income line, it can also change your eligibility for credits and deductions that phase out at higher income levels. A single pre-tax contribution can move you on multiple fronts at once. See how tax deductions differ from tax credits if you want the mechanics behind why that matters.

#What tax changes take effect in 2026?

The One Big Beautiful Bill Act (OBBBA), passed in July 2025, made most of the individual provisions from the Tax Cuts and Jobs Act permanent instead of letting them expire at the end of 2025. Combined with routine inflation adjustments, here’s what’s different for the return you’ll file in 2027:

• Standard deduction: $16,100 for single filers and married filing separately, $32,200 for married filing jointly, and $24,150 for head of household filers. These amounts increased from 2025.
• The new $6,000 senior deduction: taxpayers 65 and older can claim an additional $6,000 deduction ($12,000 for a married couple where both spouses qualify), on top of the existing standard deduction and the existing additional deduction for seniors. It phases out at higher incomes and is currently scheduled to run through 2028.
• SALT cap raised to $40,400: This is up from $10,000 before the OBBBA and $40,000 in 2025. If you own a home in a high-tax state and gave up on itemizing years ago, this is worth rechecking.
• New deductions for tips, overtime, and car loan interest: Introduced under OBBBA, all three are currently set to expire after 2028. If you qualify, this is a limited window.
• Tax brackets: The seven marginal rates stay at 10%, 12%, 22%, 24%, 32%, 35%, and 37%, with the top rate applying above $640,600 (single) or $768,700 (married filing jointly). The IRS continues to index brackets using Chained CPI, a slower-moving inflation measure than standard CPI.

Your marginal tax rate is what you pay on your next dollar of income. Your effective tax rate is your total tax divided by your total income. The effective rate is almost always lower, because the U.S. system is progressive and only the income inside each bracket is taxed at that bracket’s rate.

#Your month-by-month tax calendar

A calendar is useful in knowing when tax planning and preparation can and should be done.

• January-February – Documents arrive. Your W-2s, 1099s, and 1098s land in your inbox and your mailbox. This is also when you reconcile everything you tagged as deductible over the past year. Tag it in Monarch as it happens, and January reconciliation takes minutes instead of days. Use our tax documents checklist to make sure nothing’s missing before you go ahead and file.
  
• March-April – File, then fix (if necessary). File your return. If your refund or balance due was unusually large, don’t just bank it and move on. Instead, adjust your withholding immediately so 2026 doesn’t repeat 2025. Here’s what to actually do with your refund if you’re unsure.
  
• April – Q1 estimated tax payment due. If you’re self-employed, freelance, or have significant investment or rental income, your first quarterly payment is due alongside your filing deadline.
  
• May-June – Mid-year checkpoint. Run the IRS Tax Withholding Estimator to confirm your withholding still matches your actual situation, and check whether your retirement contributions are on pace to hit the annual limit by December. This financial spring-cleaning checklist covers the broader version of this review.
  
• June – Q2 estimated tax payment due.
  
• July-August – Life-change review. Marriage, a new baby, a new job, a home purchase are just a few examples that can change your filing status, your withholding, or what you’re eligible to deduct. This is the checkpoint to catch it before it compounds.
  
• September – Q3 estimated payment due.
  
• October-November – The real planning window. This is when the moves with the biggest impact actually happen. Now is the time to decide to bunch multiple years of charitable giving into one, timing the sale of investments for a loss, and reviewing whether you’re on pace to itemize or take the standard deduction.
  
• December – Hard deadlines. FSA funds need to be spent down (unless your plan allows a grace period or rollover), charitable gifts need to be made, and 401(k) contributions made through payroll need to be scheduled before your last paycheck of the year. RMDs, if they apply to you, are due. This end-of-year financial checklist walks through the full list.
  
• December 31 – The line that matters most. This is the hard cutoff for almost everything including 401(k) contributions, charitable gifts, FSA spending, tax-loss harvesting. Two notable exceptions are contributions to your IRA and HSA which can be made up until the tax filing deadline in April.
  
• January 15, 2027 – Q4 estimated payment due.

#What are the best ways to reduce your taxable income?

Here we’ve ranked these moves by accessibility for a typical W-2 household and not by which one saves the most for every situation.

1. Traditional 401(k). Every dollar you contribute lowers your taxable income by a dollar, before you even think about the tax-deferred growth. Take a married couple filing jointly with $120,000 in combined income, sitting in the 22% marginal bracket. If they increase their combined traditional 401(k) contributions by $6,000 – from $12,000 to $18,000 a year – their taxable income drops by $6,000, cutting their federal tax bill by $1,320. Spread over 12 months, that’s about $500 a month set aside for a real reduction of about $110 per month in take-home pay.
2. HSA. If you have a qualifying high-deductible health plan, an HSA is the only account with a triple tax advantage. With the HSA your contributions reduce taxable income, growth is tax-free, and withdrawals for qualified medical expenses are not taxed.
3. Traditional IRA. Same dollar-for-dollar reduction as a 401(k), with one caveat: if you or a spouse is covered by a workplace retirement plan, the deduction phases out at higher income levels.
4. FSA. Pre-tax dollars set aside for medical or dependent-care expenses, deducted straight from taxable income, but most plans require you to spend the balance within the year or lose it.
5. Deduction bunching. If your itemized deductions usually fall just short of the standard deduction, consider giving two years’ worth of charitable contributions in one single year, then taking the standard deduction the next. You get the bigger deduction in the year you itemize without giving any less over time.
6. Tax-loss harvesting. Selling an investment at a loss to offset gains elsewhere in your portfolio, and, within limits, to offset a portion of ordinary income. It’s a timing strategy, not a way to avoid tax altogether.
7. Income timing. If you’re self-employed or have variable income, you have more control than most over which tax year a payment lands in. Deferring December invoices to January, or accelerating deductible business expenses into the current year, can shift your bracket exposure.

A quick note on a common confusion: a Roth IRA does not reduce your taxable income. Roth contributions are made with after-tax dollars and the benefit is tax-free growth and tax-free withdrawals in retirement, not a deduction today. If lowering this year’s tax bill is the goal, the traditional versions of these accounts are where you should focus.

#Standard deduction or itemize? A four-line check

More than 90% of taxpayers take the standard deduction, and for most households, that’s the right call. Yet, the $40,400 SALT cap makes it worth rechecking if you own a home in a high-tax state. Add these four numbers:

1. Mortgage interest paid
2. State and local taxes, capped at $40,400
3. Charitable contributions
4. Medical expenses above 7.5% of your AGI

Compare the total to your 2026 standard deduction amounts (either $16,100, $32,200, or $24,150 depending on your filing status) and take whichever number is larger.

#What is tax withholding, and why does it matter?

Your W-4 tells your employer how much tax to withhold from each paycheck. Most people fill it out once when they’re hired and never touch it again, even after a raise, a marriage, a new baby, or other major life change.

The IRS Tax Withholding Estimator takes about ten minutes and tells you whether your current withholding is on track. If it’s off, you submit an updated W-4 to your employer. It’s as simple as that.

The average refund last year was $3,571 and nearly 70% of filers received one. That’s not a stroke of luck. It’s the default outcome of over-withholding, and it means most households are effectively giving the government an interest-free loan for up to sixteen-months, then calling it a refund.

The other side of this is if you withhold too little, you can owe an underpayment penalty. The IRS generally waives it if you’ve paid at least 90% of this year’s tax liability or 100% of last year’s (110% if your income is higher). This is the “safe harbor” rule. Ultimately, whether you owe or get a refund, there’s a tradeoff between having cash flow today and cash flow in April. It’s best to be intentional about it instead of by accident.

#Planning as a household

One overlooked aspect of tax planning guides is that they are often written just for single filers. When filing as a couple, it’s crucial to coordinate to avoid avoidable overpayment and underpayment issues.

#A few things worth discussing explicitly:

• Filing status. Married filing jointly is right for most couples, but married filing separately can make sense in specific circumstances. For example, high medical expenses for one spouse, student loan repayment plans tied to individual income, or separating liability. It’s worth deciding intentionally.
• Two W-4s, one household. When both partners earn income, it’s easy for withholding to be calculated as if each job were the household’s only income. The IRS estimator has a version of this calculation built to include both.
• Who claims what. Dependents, education credits, and certain deductions can only be claimed once. Deciding who claims what, and confirming both of you agree, avoids a rejected filing.
• Are you both maxing pre-tax contributions? It’s common for one partner’s 401(k) or HSA to be fully funded while the other’s sits underused. Since these accounts reduce taxable income at the household level, a shared view of both accounts is the only way to actually optimize it.

#How Monarch helps

Tax planning mostly fails for one reason: it depends on remembering in December what happened earlier in the year. Nobody keeps a running mental tally of every deductible expense across an entire year, which is why the shoebox-of-receipts scramble happens every tax filing season.

Monarch is built to close that gap as it happens, not after the fact:

• Custom tags. Create a “tax deductible” tag and apply it to transactions as they land. This could include charitable gifts, medical costs, and business expenses. This way they’re already sorted by the time January arrives.
• Saved Reports, including a year-end tax report. A report filtered to your tax-deductible tags produces the totals your preparer actually needs, without a manual reconstruction.
• Custom categories. Mirror the specific deduction categories that matter for your situation instead of working around generic buckets.
• Budgets and Goals. Set aside money for quarterly estimated payments or an expected balance due, so April isn’t a cash-flow surprise.
• Shared household view. Both partners see the same complete picture. This matters when you’re filing jointly and coordinating withholding across multiple W-4s.
• Recurring transactions. Surfaces the recurring deductible items including professional dues, subscriptions, insurance premiums, and more. These are easily forgotten by the time tax season arrives.

Your tax preparer will thank you when you arrive next tax filing season with all your information neatly organized and ready to go. You’ll also fully understand what you’re looking at before you hand it over.

#The goal isn’t a bigger refund

The goal for tax season is for there not to be any surprises. Tax planning, done throughout the year instead of the week before the deadline, is what makes a “no surprises” season possible. Most of it really comes down to a few key decisions made on schedule.

#FAQs

What is the $6,000 tax break, and who gets it?
It’s a new deduction for taxpayers 65 and older. It’s worth $6,000 per qualifying individual ($12,000 for a married couple where both spouses qualify), on top of the existing standard deduction or itemized deductions. It phases out at higher income levels and is currently scheduled to run through 2028.

Does a Roth IRA reduce your taxable income?
No, Roth IRA contributions are made with after-tax dollars, so they don’t lower your taxable income in the year you contribute. The benefit is tax-free growth and tax-free qualified withdrawals in retirement. If you want to reduce this year’s taxable income, a traditional IRA or 401(k) does that instead.

Does a 401(k) reduce your taxable income?
Yes, but only a traditional 401(k). Every dollar contributed reduces your taxable income for the year, dollar-for-dollar. A Roth 401(k) does not, for the same reason a Roth IRA doesn’t.

What is the most overlooked tax break?
For homeowners in high-tax states, it’s the raised SALT cap, which is now $40,400. More broadly, mid-year adjustments to retirement contributions are consistently underused simply because most people only think about taxes in the spring.

Should I aim for a big refund or a small one?
Neither, really. The primary goal is accuracy. A large refund means you overpaid all year and gave the government an interest-free loan. A large balance due (beyond what the safe harbor rule allows) can trigger a penalty. The IRS Tax Withholding Estimator is built to get you close to zero on both ends.

What’s the difference between tax planning and tax preparation?
Tax preparation is recording what already happened (like gathering documents and filing an accurate return). Tax planning is changing what is going to happen (decisions made throughout the year, most with a December 31st deadline) that determine what ends up on that return in the first place.

Do I need to make quarterly estimated payments?
If you’re self-employed, freelance, or have significant income that isn’t subject to withholding (rental income, investment income, a side business) then you likely need to pay estimated taxes quarterly (typically in April, June, September, and January) to avoid an underpayment penalty.