Nobody Withholds Anything Unless You Ask

What will I owe this year?

For forty years, taxes handled themselves. Money came out of every paycheck before you saw it. You filed in April, got a refund or wrote a modest check, and never thought about it in between.

Retirement quietly ends that arrangement, and most people don't notice until the bill arrives.

Now nothing is withheld unless you specifically ask for it. Your IRA custodian withholds only what you tell them to. Social Security withholds nothing by default. Your brokerage withholds nothing on dividends or capital gains at all. The system switched from automatic to self-service, and nobody sent a notice.

That's the first reason to do this in July.

The second reason: December is too late

Every decision left in the year depends on one number — what your income is going to be.

Whether a Roth conversion makes sense, and how large. Whether you're near a Medicare threshold. Whether harvesting a loss helps. What to do about required distributions. All of it rests on knowing where you're going to land.

Build that number in July and you have five months to act on it. Build it in December and you're not planning, you're reporting.

What actually goes in the projection

List every source and be complete about it, because the ones people forget are the expensive ones:

Social Security, both spouses. Pension. Every withdrawal from a retirement account, including required distributions. Interest. Dividends. Rental income. Any part-time work. Any Roth conversion you've already done or intend to.

And two that almost always get missed:

Realized capital gains, including from anything you sold earlier in the year and have half forgotten.

Mutual fund capital gain distributions. If you hold mutual funds in a taxable account, they distribute gains in December whether you sold anything or not. You can receive a substantial taxable distribution in a year you did nothing at all. Check last year's 1099 for a sense of scale.

Then check what you're actually paying in

Add up everything being withheld — from Social Security, from pension payments, from IRA distributions — plus any estimated payments you've already made.

Compare it to the tax your projection implies. The difference is your gap, and now is when it's fixable.

The safe harbor is what you actually need to hit

You don't have to predict your tax perfectly. There's a rule that protects you, and it's more generous than most people realize.

No underpayment penalty if you pay in at least:

100% of last year's total tax — or 110% if your income last year was above $150,000. This is the practical one, because you already know last year's number. It's sitting on your return.

Or 90% of this year's actual tax. Harder, since you're estimating.

You also owe no penalty if you end up owing less than $1,000 after withholding.

The prior-year test is the one to aim at. It's a fixed target, you know it today, and it holds no matter how much your income rises this year. Hit it and you can owe a large amount in April with no penalty at all — you just need the cash ready.

What the penalty actually costs

It isn't a flat fine. It's interest, charged on each shortfall from the date it was due.

The rate is set quarterly at the federal short-term rate plus three points. In 2026 it's been running between 6% and 7%. On a $6,000 shortfall carried most of a year, that's a few hundred dollars — annoying rather than devastating, but entirely avoidable.

The four ways to pay, and why one is better

Withholding from IRA distributions — Form W-4R. You choose the percentage. The default is 10% unless you elect otherwise, and you can elect nearly any amount.

Withholding from Social Security — Form W-4V. Limited to four choices: 7%, 10%, 12%, or 22%. That's it, so it's a blunt instrument.

Withholding from a pension — Form W-4P.

Quarterly estimated payments — Form 1040-ES, due in April, June, September, and January.

Now here's the thing worth knowing, because it's the most useful fact in this brief.

Withholding is treated as if it were spread evenly across the year

No matter when it actually happens.

Take an IRA distribution on December 20th and withhold $12,000 from it, and the IRS treats that as though you'd paid $3,000 in each quarter. It cures shortfalls going all the way back to April.

Estimated payments don't work that way. They're credited when you make them. A large payment in January doesn't fix an April underpayment — the interest already ran.

So if you reach the autumn and discover you're behind: don't send an estimated payment. Take a distribution and withhold heavily from it. Same money, and the timing problem disappears.

For many retirees the simplest system is to skip quarterly payments entirely and cover the whole year's tax through withholding on a December distribution. One transaction. No calendar to keep.

One thing not to withhold from

If you're doing a Roth conversion, pay the tax from a taxable account rather than withholding from the conversion itself.

Money withheld from a conversion doesn't reach the Roth — it's a distribution that goes to the IRS. So you convert less than you intended, and the tax-free growth on that amount is lost permanently. If you're under 59½, the withheld portion can also carry a 10% penalty.

Convert the full amount. Pay the tax from elsewhere. It's a small mechanical detail that costs real money when it's missed.

The years that catch people out

Certain years produce surprises, and they're predictable:

Your first year of required distributions. A new stream of income with nothing withheld against it.

Your first year of Social Security, when the taxability of the benefit surprises people.

A year with a Roth conversion and no plan for the tax.

A year you sold property, where the capital gain lands with no withholding at all.

A year a spouse died, where the survivor's filing status changes and everything shifts. That's June's month, and this is where it shows up in dollars.

What July is for

One page. Every income source, what's realistic for the rest of the year, and the total.

Then compare what's being withheld against what you'll owe, check yourself against the safe harbor, and correct it while there's time.

That number is the input for everything left in the year. August can't size a conversion without it. September can't tell you where you stand against a Medicare threshold. November can't be planned.

Build it now, and the rest of the year gets much easier.