Guides · Tax myths

Common tax myths — and the corrections

Tax myths persist because the underlying systems are genuinely complex. People hear a fragment, repeat it, and pass it on. Each myth below is one that the TaxToNet team sees regularly in user questions, blog comments, social media, or well-meaning advice from friends and family. The corrections cite the calculator, the methodology, or a primary government source.

United States myths

Myth: "All my income is taxed at my top bracket."

Wrong. The US uses progressive brackets, like most modern income tax systems. Only the slice of income within a band is taxed at that band's rate. Someone in the 24% federal bracket for tax year 2026 pays 10% on the first slice, 12% on the next, 22% on the next, and 24% only on the slice above $103,350 (single, per Rev. Proc. 2025-32).

The TaxToNet calculator walks through this band-by-band in every result. Use the US calculator to see the math.

Myth: "A bigger refund means I got a bonus."

Wrong. A refund is the government returning money you already paid during the year. There is no bonus, no gift, and no thanks — only your own money back, with no interest. The "bonus" framing is the one that has caused the most consumer misunderstanding of the tax system.

Myth: "I only owe tax if I cash a paycheck cheque."

Wrong. Direct deposit, paper cheque, or cash — none of that changes your tax liability. What matters is the gross amount paid to you, not the payment rail. Direct deposit is just the rail the IRS sees via W-2 Box 1.

Myth: "I should reduce my W-4 to zero to keep more in my pocket."

Risky. A W-4 with zero allowances (pre-2020 design) or a "no withholding" checkbox (post-2020 design) is legitimate for people with no tax liability, but it is not a get-out-of-jail card. If your real liability is positive, reducing W-4 to zero produces a balance due at year-end plus underpayment penalties. The IRS Tax Withholding Estimator is the official tool for setting the right number.

Myth: "401(k) contributions reduce my take-home by 22% (or whatever my bracket is)."

Wrong (sort of). A traditional 401(k) contribution does not "reduce" your take-home by your marginal bracket. The contribution itself comes out of your pay dollar for dollar, but the tax saving reduces your total out-of-pocket cost. A 5% contribution to a 401(k) at the 22% bracket costs you about 3.9% of take-home (5% contribution - 1.1% in combined federal income tax and FICA savings). The exact arithmetic depends on your bracket, state tax, and any employer matching — but the 22% intuition is wrong.

Myth: "Capital gains are taxed at the same rate as wages."

Mostly wrong. Long-term capital gains (assets held more than one year) are taxed at preferential rates — 0%, 15%, or 20% at the federal level depending on income. Short-term capital gains (held one year or less) are taxed as ordinary income. State tax treats capital gains as ordinary income in most states. The Net Investment Income Tax adds 3.8% on investment income above $200,000 single / $250,000 married filing jointly.

Myth: "Social Security benefits are not taxable."

Wrong. Up to 85% of Social Security benefits can be taxable at the federal level, depending on your combined income. The threshold for the first dollar of taxable benefit is $25,000 single / $32,000 married filing jointly (these thresholds have not changed since 1993). Up to 50% of benefits become taxable above that; up to 85% above the second threshold. State tax varies — most states do not tax Social Security benefits.

Myth: "If I move to a no-income-tax state, I'll save 13%."

Often wrong. Relocation decisions involve more than income tax. Property tax, sales tax, housing cost, healthcare, and the cost of state-funded services all differ. A full relocation analysis should weigh all of those, not just the income-tax headline.

United Kingdom myths

Myth: "The 40% higher rate kicks in at £40,000."

Wrong. The higher rate (40%) starts at £50,270 in 2026/27 — and that is for England, Wales, and Northern Ireland. Scottish residents face different bands (Scottish income tax is devolved and produces a higher effective rate at lower incomes). TaxToNet models E/W/NI bands; Scottish rates are explicitly out of scope.

Myth: "I take home 60% on £50,000."

Wrong. At £50,000 gross in 2026/27, you take home about £39,300 net (single, E/W/NI). That is roughly 79% of gross, not 60%. The "60%" comes from confusing the marginal rate (40% on the slice above £50,270) with the effective rate. See the marginal vs effective guide.

Myth: "If I earn £100,000, I lose 60p of every £1 over £100k."

Mostly right, but worth being precise. The Personal Allowance taper removes £1 of allowance for every £2 of adjusted net income above £100,000, up to £125,140 where the allowance is £0. The withdrawn allowance is taxed at 40% (basic rate), giving a marginal rate of 60% on income tax alone. Add 2% NI and the combined marginal is 62%. That arithmetic is correct.

What is wrong about the myth: it implies a flat 60% on every £1 over £100k. The taper is gradual — it does not "kick in" cleanly at £100,001. The first £1 over £100,000 loses £0.50 of allowance (and £0.20 of tax on that withdrawn allowance); the marginal rate builds. The full 60% only applies from £125,140 onwards (where the taper is complete).

TaxToNet does not model the taper in v1; see assumptions.

Myth: "Salary sacrifice is the same as a pension contribution."

Almost. Salary sacrifice is a specific mechanism where you agree to give up part of your salary in return for a non-cash benefit (pension contributions, childcare vouchers, cycle-to-work, EV lease). Pension contributions can also happen via relief-at-source (post-tax pay, with HMRC adding 20% basic-rate relief).

Salary sacrifice is more tax-efficient because it also avoids NI on the contribution. A £1,000 salary-sacrifice pension contribution saves an additional £80-$160 (depending on NI band) over a relief-at-source contribution.

Myth: "Dividends are tax-free."

Wrong. The UK has a £500 dividend allowance (2026/27), but dividends above that are taxed at 8.75% (basic rate), 33.75% (higher rate), or 39.35% (additional rate). Dividends paid within an ISA or pension are not taxable. TaxToNet does not model investment income.

Myth: "Capital gains are 18% in the UK."

Partly wrong. Residential property gains are taxed at 18% (basic) / 24% (higher) for 2026/27. Other gains — shares held outside an ISA, for example — are taxed at 18% / 24% for chargeable gains above the £3,000 annual exempt amount. The headline rate you may have heard (28% / 24% for property) is the historic rate, not the current rate.

Myth: "I can avoid tax by gifting to my spouse."

Right, mostly. Transfers between UK spouses/civil partners are generally exempt from income tax and capital gains tax. There is no annual limit. The recipient is treated as having the transferred income or asset for their own tax position. This is a useful planning tool — not a myth.

Cross-country myths

Myth: "Income tax rates in the US are higher than the UK."

It depends. The US top federal rate is 37% at $609,350+ single (2026). The UK higher rate is 40% from £50,270 and additional rate is 45% from £125,140. Add NI (2% above £50,270) and the UK top combined marginal rate is 47%. Add state tax in California or New York, and the US combined can exceed 50%.

The rates are not directly comparable — the bands, allowances, social contributions, and state tax layers all differ. Use the TaxToNet calculators to model specific scenarios.

Myth: "I can dodge US tax by moving abroad."

Wrong. US citizens are taxed on worldwide income for life, regardless of where they live. The Foreign Earned Income Exclusion (FEIE, $130,000 for 2026) and Foreign Tax Credit reduce double taxation but do not eliminate the US filing obligation. Some people move abroad and stop filing; this is one of the most common ways US citizens accidentally become non-compliant. The IRS actively identifies and pursues these cases.

Myth: "The calculator shows me exactly what I'll owe."

Wrong. The TaxToNet calculator shows a clean, single-filer, employment-income baseline. It does not model state tax (US), pre-tax deductions, credits, investment income, capital gains, self-employment, or filing-status variants. Use the result as a reference number, not a substitute for Form 1040 / SA100.

Myth: "Tax software always agrees with the calculator."

Often, but not always. Tax software applies the same brackets, but it also includes credits, deductions, and quirks that the calculator does not. If the calculator shows $9,000 and TurboTax/HMRC says $7,500, the difference is real — the software is including things the calculator does not model. The calculator is a baseline, not a substitute.