Preliminary Work and Taxpayer Data · Preliminary work to prepare tax returns
Taxpayer biographical information
tax year · reviewed 2026-08-19 · I. Ohu
The rule
Biographical intake is not clerical work. Each fact collected decides something: date of birth drives the age tests and the additional standard deduction, marital status on the last day of the year decides filing status, residency and citizenship decide whether worldwide income is reported, and the identifying numbers decide whether credits are allowable at all.
Identifying numbers are a statutory requirement. IRC § 6109(a) requires a person making a return to include the identifying number prescribed for securing proper identification, to furnish their number to a person who must show it on another return, and to request and include the number of another person about whom they are making a return. Section 151(e) adds that no exemption is allowed with respect to an individual unless that individual's TIN is included on the return claiming itTY2026.
Two credits impose stricter number rules than § 6109 does, and the difference is where returns are actually lost:
- Child tax credit. No credit is allowed with respect to a qualifying child unless the return includes the taxpayer's social security number — or, on a joint return, that of at least one spouse — and the social security number of the qualifying childTY2026 (IRC § 24(h)(7)(A)). The definition in subparagraph (B) narrows it further: the number must have been issued by the Social Security Administration to a citizen, or under the provisions relating to lawful admission for employment.
- Earned income credit. Under IRC § 32(m) the identification number must be a social security number issued by the Social Security Administration, other than one issued solely for non-work purposes, on or before the due date for filing the return for the taxable yearTY2026. Two conditions are doing work there: a number issued solely for non-work purposes does not count, and the number must exist on or before the due date — obtaining it later does not retroactively qualify the year.
An ITIN satisfies neither of these. It is a valid identifying number for filing under § 6109 and for claiming a dependent, but it does not support the child tax credit or the earned income credit.
Current figures
| Item | Requirement |
|---|---|
| Exemption / dependent claim | no exemption is allowed with respect to an individual unless that individual's TIN is included on the return claiming itTY2026 |
| Child tax credit | the taxpayer's social security number — or, on a joint return, that of at least one spouse — and the social security number of the qualifying childTY2026 |
| Earned income credit | a social security number issued by the Social Security Administration, other than one issued solely for non-work purposes, on or before the due date for filing the return for the taxable yearTY2026 |
| Identity protection PIN validity | a six-digit number valid for one calendar year, with a new one generated each year; it is used only on Forms 1040, 1040-NR, 1040-PR, 1040-SR and 1040-SS, must be used on any federal return filed during the year including prior-year returns, and is generally viewable in the online account from mid-January through mid-NovemberTY2026 |
| IP PIN — forms it is entered on | Forms 1040, 1040-NR, 1040-PR, 1040-SR and 1040-SS onlyTY2026 |
| IP PIN — online availability | generally viewable in the online account from mid-January through mid-NovemberTY2026 |
How it works in practice
Collect the facts that change the return, and know which ones the Code compels. The minimum a return itself requires is the taxpayer’s legal name, identifying number, filing status and address, together with the name and identifying number of every dependent claimed. Everything else on a practitioner’s intake sheet — date of birth, marital status, residency, citizenship — is collected because it determines the answers, not because the return has a box demanding it.
A social security card is not required; the number is. This distinction is worth being precise about because it is easy to overstate in either direction. Nothing in § 6109 or § 151(e) requires the taxpayer to produce the physical card, and the number may be supplied verbally or in writing. What is required is that the correct number appear on the return.
But asking to see documents is good practice, and a separate rule. Publication 1345 directs an ERO to confirm identities and taxpayer identification numbers, and says an ERO should ask taxpayers not known to them to provide two forms of identification — photo identification preferred — showing the name and a current or recent address. That is guidance addressed to the preparer as a fraud safeguard, and it is a “should” rather than a “must”. It is not a condition of filing, and describing it as one confuses a professional standard with a statutory requirement.
Transcribe the number exactly as the source document shows it. Publication 1345 warns that incorrect numbers, the same number used on more than one return, and the wrong name associated with a number are among the most common causes of rejected returns. The Name Control — the first four significant letters of the surname as the Social Security Administration records it — causes a large share of them, most often for a newly married taxpayer whose SSA record has not been updated.
The identity protection PIN belongs in the intake file. An IP PIN is a six-digit number known only to the taxpayer and the IRS. It is a six-digit number valid for one calendar year, with a new one generated each year; it is used only on Forms 1040, 1040-NR, 1040-PR, 1040-SR and 1040-SS, must be used on any federal return filed during the year including prior-year returns, and is generally viewable in the online account from mid-January through mid-NovemberTY2026. It is used on Forms 1040, 1040-NR, 1040-PR, 1040-SR and 1040-SS onlyTY2026, must be used on any federal return filed during the year including prior year returns, and is generally viewable in the online account from mid-January through mid-NovemberTY2026. A missing or incorrect IP PIN rejects an e-filed return and delays a paper one. The programme is now open to anyone who can verify their identity, as a protective step rather than a remedy — which makes recommending it a reasonable part of intake for any client.
Date of birth does more than the age tests. It drives the additional standard deduction for the aged, the new deduction for seniors, the retirement distribution rules, and the qualifying child age test. A birthday falling on 1 January is the classic trap: a person is treated as reaching a given age on the day before their birthday, so someone born on 1 January is 65 for a year in which their birthday falls on the first day of the following one.
The card that was never produced
A long-standing client telephones her figures through and gives her new grandson’s social security number verbally so that he can be claimed as a dependent. The preparer hesitates, believing the card must be seen.
The Code requires the number on the return, not the card in the file. Section 6109 obliges the taxpayer to furnish the number and the preparer to include it; § 151(e) denies the claim if it is absent. Nothing requires the physical document. What Publication 1345 recommends — sight of the card or similar documents, and two forms of identification for a taxpayer not known to the ERO — is a fraud safeguard aimed at getting the number right, and it earns its place for that reason rather than as a legal condition. The practical answer is to ask for a copy because transcription errors reject returns, while being clear that the requirement is accuracy, not documentation.
The ITIN that could not carry the credit
Esperanza Villanueva-Achebe files with an ITIN and claims her two children, who each hold an ITIN as well. She expects the child tax credit.
The dependency claims are fine — an ITIN is a valid identifying number for that purpose. The credit is not. Section 24(h)(7) requires the social security number of the qualifying child, and since the 2025 amendment it also requires the taxpayer’s own social security number, or that of at least one spouse on a joint return. ITINs satisfy neither leg. The same result follows for the earned income credit under § 32(m). This has to be explained at intake, because the alternative is a client who budgets around a refund that will not arrive.
The number that arrived in June
Kwabena Lindqvist-Osei’s daughter’s social security number was applied for late and issued in June, after the April due date. He filed an extension and now files in September claiming the earned income credit.
The credit is unavailable for that year. Section 32(m) requires the number to have been issued on or before the due date for filing the return for the taxable year, and an extension does not move that date for this purpose. The number is valid going forward, so the following year is unaffected. Where a practitioner learns of a pending application before the due date, the advice is about the application timeline rather than about the return — which is why this is an intake question, not a filing-season one.
How this has changed
Public Law 119-21, enacted 4 July 2025, made three changes to the child tax credit that bear on intake, and the identifying-number change is the one that belongs here. Section 70104(b) amended § 24(h)(7) generally; before the amendment the paragraph allowed the credit if the taxpayer included the social security number of the qualifying child, and it now requires the taxpayer’s own number — or at least one spouse’s on a joint return — in addition. A preparer working from a remembered rule will collect one number where two are needed.
The same Act made the § 24(h) regime permanent by striking the 1 January 2026 sunset, and raised the credit. Those figures belong to the child tax credit topic rather than this one, but they are recorded here because they were verified in the same reading: the maximum credit for 2026 is 2,200 dollars and the refundable portion is 1,700 dollars, per Rev. Proc. 2025-32 § 3.05.
On the identity side the direction has been steadily toward verification. The IP PIN began as a remedial measure for confirmed identity theft victims and is now available to anyone who can verify their identity; the ERO identity-checking guidance in Publication 1345 has expanded with each revision; and from 2024 returns the IRS began accepting an e-filed return claiming an already-claimed dependent where the primary taxpayer includes a valid IP PIN.
Exam focus
Know that the identifying number is required on the return and the physical card is not, and that the two-forms-of-identification guidance is a preparer recommendation from Publication 1345 rather than a filing requirement. Know that an ITIN supports filing and dependency claims but not the child tax credit or the earned income credit. Know that the earned income credit number must be issued on or before the due date. Expect date of birth, marital status and residency to appear as facts that determine some other answer rather than as topics in themselves.
Check yourself
1. Which is not a minimum requirement for filing a return?
A. Providing a social security card B. The taxpayer’s date of birth as an intake fact C. The identifying number of each dependent claimed D. The taxpayer’s filing status
Answer: A. The number must appear on the return; the physical card need not be produced and may be supplied verbally or in writing.
2. A taxpayer and both children hold ITINs. Which is available?
A. The child tax credit B. The earned income credit C. A dependency claim for each child D. All of these
Answer: C. An ITIN is a valid identifying number for filing and for claiming a dependent, but § 24(h)(7) and § 32(m) each require a social security number.
3. What does IRC § 24(h)(7) require on the return as rewritten?
A. The qualifying child’s social security number only B. The taxpayer’s social security number only C. The taxpayer’s social security number — or one spouse’s on a joint return — and the child’s D. An ITIN for either the taxpayer or the child
Answer: C.
4. A qualifying child’s social security number is issued two months after the return’s due date. What is the effect on the earned income credit for that year?
A. The credit is allowed once the number is obtained B. The credit is allowed if an extension was filed C. The credit is not allowed for that taxable year D. The credit is allowed at half the amount
Answer: C. Section 32(m) requires the number to be issued on or before the due date for filing the return for the taxable year.
5. Publication 1345 says an ERO should ask a taxpayer not known to them for two forms of identification. What is the status of that guidance?
A. A statutory condition of filing a return B. A preparer safeguard against identity theft refund fraud C. A requirement only for paper returns D. A condition of claiming any refundable credit
Answer: B. It is addressed to the provider as a fraud safeguard, not to the taxpayer as a filing requirement.
Change log
- Initial draft. Records that Pub. L. 119-21 § 70104(b) rewrote IRC § 24(h)(7) to require the taxpayer's own social security number in addition to the child's.
Related topics
- Residency status and/or citizenship (e.g., citizen, visas, green cards, resident alien or non-resident alien, ITIN) 1.1.1.c
- Qualifications for dependency 1.1.1.i
- Taxpayer filing status (e.g., single, head of household) 1.1.1.e
- Minor children's unearned income (Kiddie tax) 1.1.1.p
- ACA requirements (e.g., health insurance coverage, total household income, advanced premium tax credit, household size) 1.1.1.q
- Previous IRS correspondence with taxpayer 1.1.1.l