Dependent Care FSA With a Nanny: Receipts and Provider ID

What your administrator is actually checking

A dependent care flexible spending account is an employer plan under section 125 of the tax code, and section 125 plans are not permitted to let you certify your own expenses. Every reimbursement has to be substantiated by an independent third party, which in your case means the nanny. That single rule explains almost every rejection letter parents receive.

The administrator is looking for four facts on one document: who provided the care, who received it, exactly when, and how much was paid. A payment record proves only that money moved. It does not say what the money bought or when the service happened, which is why a cancelled check image, a Zelle or Venmo screenshot, or a highlighted line on a bank statement is almost always kicked back on its own. Attach one as supporting evidence if you like, but it cannot carry the claim.

Rejected on sight

• A bank transfer, cancelled check or card statement with no provider statement attached.
• An employment contract or agreed rate sheet. That is a promise of future care, not a record of care given.
• An invoice dated ahead of the service period. Dependent care expenses have to be incurred before they are reimbursed, so a claim filed on the first of the month for that whole month fails on timing alone.
• A statement with no provider taxpayer ID. Most administrators treat a missing TIN as fatal, because the plan has to be able to report the benefit correctly.

Accepted

• An itemised invoice or receipt from the nanny carrying all eight fields in the table below, signed by her.
• Your plan's own dependent care claim form, with the provider section completed and signed in her hand rather than yours.
• A recurring claim authorisation, if your plan offers one, covering a fixed weekly schedule. It still needs the provider signature and TIN, and it still only pays out after each period has passed.
• A payroll report from a household payroll service, which usually satisfies every field at once because it already carries the legal name, the TIN, the pay period and the gross wage.

The receipt template, field by field

There is no official IRS receipt form for this. Any document carrying these fields will do, which is why the template sites selling you a fillable PDF are selling you a layout you could write in a text editor in five minutes. What matters is the content and the signature.

Field requirements below reflect what dependent care plan administrators commonly ask for. Your own plan document governs, so check its claim rules before you file.

File weekly or monthly, in arrears, and have the nanny sign as she is paid rather than chasing eleven months of signatures in December. Signatures gathered long after the fact, for periods a provider can no longer remember, are exactly what substantiation rules exist to catch.

The provider taxpayer ID, and why Form W-10 exists

Satisfying your administrator is only half of it. If you received dependent care benefits through an FSA, you also have to file Form 2441 with your return. Part I of that form asks for the care provider's name, address and taxpayer identification number. For an individual nanny, the TIN is her Social Security number. Part III is where the FSA money you excluded from income gets reconciled against qualifying expenses, and a benefit that cannot be reconciled becomes taxable wages.

Form W-10, Dependent Care Provider's Identification and Certification, is the mechanism for requesting that number. You do not send it to the IRS. You hand it to the nanny, she completes and signs it, and you keep it in your records. Its value is evidentiary. Section 6109 obliges a care provider to furnish a valid TIN, and if she refuses, a retained W-10 request is what demonstrates the due diligence that keeps your credit or exclusion from being disallowed outright. In that situation you still file Form 2441 with the provider's name and address and note that the number was requested and not supplied.

Ask for the W-10 during hiring, alongside the I-9 and the W-4. Asking for it in April, after a year of informal payment, is when the conversation goes badly.

Worked example: going legal on 1 July

Take a family paying a nanny $1,000 a week in cash. They decide in June that they want the FSA, so they put her on payroll from 1 July. Twenty-six weeks remain, so $26,000 of gross wages runs through payroll in the second half of the year. Here is what the employer side of that costs.

Figures below are estimates compiled from published averages, not quotes for your area. Get real numbers from local providers before budgeting.

Now the other side. Under the One Big Beautiful Bill Act, the dependent care FSA limit rose from $5,000 to $7,500 for tax years beginning on or after 1 January 2026, with $3,750 for married taxpayers filing separately. That was the first increase since 1986. Two cautions before you plan around it: your employer is not obliged to raise its plan ceiling to match the statute, so confirm your own plan's number rather than assuming $7,500, and the exclusion is separately capped by the earned income of the lower-earning spouse.

Suppose the plan does allow $7,500 and the family contributes the full amount. A household in a 22% federal bracket avoids roughly $1,650 of federal income tax, about $574 of employee Social Security and Medicare tax, and perhaps $375 of state income tax at a 5% rate. Call it $2,300 to $2,900 depending on the state and the bracket.

So across that second half-year the two sides roughly cancel. An FSA saving of about $2,600 sits against added employer costs of about $2,800 to $4,600, which puts the family somewhere between a small win and a loss of a couple of thousand dollars. Extend it to a full year at $52,000 of wages and the arithmetic gets worse rather than better: employer FICA alone is close to $3,980, and the total employer burden lands somewhere around $5,000 to $7,500, while the FSA saving stays fixed at roughly $2,600 because the contribution is capped.

The conclusion is uncomfortable but worth stating plainly. The dependent care FSA offsets perhaps a third to a half of what it costs to employ a nanny legally. It is a meaningful discount, not a wash, and anyone selling the FSA as the reason to go on the books has done the sum wrong. The reasons to go on the books are that it is the law, that it gives your nanny a work history, unemployment cover and Social Security credits, and that it removes a liability which compounds quietly every year you leave it. Our state-by-state workers' compensation guide covers the insurance line above, which is the item most often left out of these calculations entirely.

FSA or the credit, but not on the same dollars

The Child and Dependent Care Credit and the FSA exclusion draw on the same pool of expenses, and Form 2441 is built to enforce that. The credit is calculated on qualifying expenses capped at $3,000 for one qualifying person and $6,000 for two or more, and every dollar of employer dependent care benefit you excluded reduces that cap dollar for dollar.

The higher 2026 FSA limit changes this interaction in a way that is easy to miss. At the old $5,000 ceiling, a family with two children still had $1,000 of expenses left under the $6,000 cap to claim a small credit on. At $7,500 the exclusion exceeds the credit cap for one child and for two, so a family that maxes the FSA has no credit-eligible expense left at all. If you were counting on both, redo the sum.

Which way the trade falls also depends on your bracket. The exclusion is worth your marginal rate plus payroll tax plus state tax, so it favours higher earners. The credit is a percentage of expenses that falls as income rises, and the One Big Beautiful Bill Act raised the top credit rate above the previous 35% from 2026, with the floor staying at 20%. For a lower-income household the credit can therefore be worth more than the exclusion on the same spending. Confirm the rate table in IRS Publication 503 for the year you are actually filing before you commit to an election, and see our childcare tax credits guide for how the two stack up against each other.

Two more mechanics are worth knowing before you elect. FSA money is use-or-lose: contribute for care you do not end up buying and the balance is forfeited at the end of the plan year, subject to any grace period your plan offers. And the election is not entirely locked. Dependent care plans generally permit a mid-year election change on a significant change in the cost or coverage of care, which moving a nanny onto formal payroll may well be, though the cost provision does not apply where the provider is a relative. Ask your benefits administrator rather than assuming either way.

Confirm these figures before you rely on them

Thresholds move, and plan documents lag the statute. The 2026 figures used above are the $7,500 FSA ceiling with $3,750 for married filing separately, the $3,000 household employee cash wage threshold for Social Security and Medicare, the $1,000 quarterly threshold for federal unemployment tax, and the 7.65% employer share of FICA. The credit expense caps of $3,000 and $6,000 are unchanged. The top credit percentage was raised for 2026, and the published rate table is the place to confirm what applies at your income, since the current edition of Publication 503 may still describe the prior year. Check each of these against the IRS page for your filing year and against your own plan document, which is free to be more restrictive than the statute but never more generous.

For the wage side of the budget rather than the tax side, our nanny cost guide and the breakdown of what nanny benefits cost cover what sits on top of the hourly rate. To weigh the whole package against a centre place, start with the cost calculator.