What Documents You Need to Claim Your Children on Your Tax Return

The documents the IRS requires to claim children

To claim a child on your tax return, you need three things: proof of the child's identity, proof of your relationship to the child, and proof that you paid for their care or support. The IRS does not require you to send these documents with your return — you keep them at home — but you must have them ready if the IRS asks. The most common documents are a birth certificate, Social Security card, and receipts or statements showing you paid for housing, food, medical care, or school.

You do not need original documents. Copies are fine. If you do not have a particular document, other paperwork can substitute — for example, a school enrollment form can stand in for a birth certificate if you do not have one. The key is being able to prove three separate facts: who the child is, that you are related, and that you supported them.

Key Takeaways

• You must keep proof of the child's Social Security number, your relationship to them, and that you paid for their support — but you do not mail these to the IRS unless asked.
• A birth certificate, Social Security card, and one year of household bills or receipts cover the basic requirement for most families.
• If you do not have a birth certificate, school records, medical records, or a passport can prove the child's identity instead.
• Guardianship papers, adoption papers, or court custody orders prove your relationship if the child is not your biological child.
• The IRS may request these documents months or years after you file, so keep them for at least three years after filing.

Proof of the child's identity and Social Security number

The IRS needs to know who the child is and that they have a valid Social Security number. A Social Security card is the clearest proof, but you can also use a passport, a state ID card, or a school enrollment document that shows the child's name and date of birth.

If the child does not have a Social Security number yet, you can still claim them — but you must have applied for one before you file your return. The IRS will not accept a return that claims a child without a Social Security number, even if you applied for one after filing. If you are expecting a child and plan to claim them, apply for their Social Security number as soon as you have a birth certificate.

Keep a copy of whichever document you use. If you have the Social Security card, store it somewhere safe and keep a photocopy with your tax records. If you use a school record or passport instead, one copy in your files is enough.

Proof of your relationship to the child

The IRS needs to know that you are the parent, stepparent, grandparent, or legal guardian. A birth certificate listing you as the parent is the standard proof. If you are not the biological parent, you need different documents depending on your situation.

If you are a stepparent, a marriage certificate showing you married the child's biological parent is usually sufficient. If you are a grandparent or other relative raising the child, a custody order from a court, a guardianship document, or an adoption decree proves your legal relationship. If you have informal custody — the child lives with you but there is no court order — you may need to provide multiple documents together, such as school records showing your address, a lease or mortgage in your name, and a statement from the child's other parent or a relative confirming the arrangement.

Keep the original or a certified copy. For birth certificates and court orders, you can request certified copies from the vital records office in the state where the child was born or the court that issued the order. These cost a small fee but are worth having because they carry more weight than photocopies if the IRS questions your claim.

Proof that you paid for the child's support

You must show that you paid for more than half the child's living expenses during the year. This includes rent or mortgage, utilities, food, clothing, medical care, school tuition, and childcare. You do not need receipts for every dollar — the IRS understands that some support is hard to document — but you need enough paper trail to show the pattern.

Household bills in your name are the easiest proof. Keep one year of statements from your utility company, internet provider, or mortgage or rental payment records. These show you maintained a home where the child lived. Medical bills, school tuition statements, and childcare invoices directly prove you paid for the child's care. Grocery store receipts are harder to use because they do not show who ate the food, but a year of credit card or bank statements showing regular grocery purchases can support your claim.

If you receive child support from the other parent, that counts toward support too — but you need to document it. A child support order, bank deposits showing regular payments, or a statement from the other parent can all prove this. If the other parent claims the child instead of you, ask them to sign a form stating they will not claim the child, so there is no conflict when you file.

What to do if you are missing a document

If you do not have a birth certificate, you can request one from the vital records office in the state where the child was born. This usually takes two to four weeks and costs between $15 and $30. If you need it faster, many states offer expedited service for an extra fee.

If you cannot get a birth certificate in time to file, use what you have. A school enrollment form, a medical record, a passport, or even a hospital discharge record can prove the child's identity. Write a note with your return explaining what you used instead and why. The IRS may ask for more documentation later, but you can file now.

If you do not have a Social Security card but have a Social Security number, a tax return from a previous year, a W-2 form, or a letter from Social Security showing the number is enough. If the child has never had a Social Security number, apply for one immediately — you cannot claim the child without one.

If you do not have a custody order or guardianship papers, gather what you do have: school records in your name and address, utility bills, medical records showing you as the emergency contact, and a written statement from a relative or the other parent confirming you have custody. These together can demonstrate your relationship and support, though the IRS may follow up with questions.

How long to keep these documents

Keep all documents for at least three years after you file your return. The IRS has three years to audit most returns, though it can go back further if it suspects fraud. If you claimed the child for multiple years, keep the documents for each year separate and labeled.

Store originals in a safe place — a fireproof box, a safe deposit box, or a secure digital folder. Keep photocopies with your tax records. If the IRS requests documents, you will have them ready, and the process will move much faster.

Documents you do not need

You do not need to send documents with your tax return. The IRS does not ask for them upfront. You only need them if the IRS contacts you to verify your claim, which happens in a small percentage of returns.

You do not need a letter from the child's school, a statement from a doctor, or a letter from the other parent — though any of these can help if questions come up. You do not need to prove the child lived with you for a specific number of days, though you must show they lived with you for more than half the year. You do not need receipts for every expense, just enough documentation to show the pattern of support.

Frequently Asked Questions

Can I claim my grandchild if I do not have guardianship papers?

You can, but you will need to prove your relationship and support another way. Gather school records showing your address, utility bills, medical records listing you as the emergency contact, and a written statement from the child's parent or a relative confirming you provide the child's main support. The IRS may ask follow-up questions, but these documents together can establish your claim.

What if the child's other parent also claims them on their return?

The IRS will reject one of the returns or ask both of you to prove your claim. Before filing, ask the other parent to sign a form stating they will not claim the child. If you cannot reach them, file your return and keep documentation showing you paid for support. The IRS will contact whoever filed second and ask for proof.

Do I need to send copies of documents with my return?

No. Keep them at home. The IRS only asks to see them if it audits your return or has questions about your claim. Sending them unprompted can actually slow down processing. Wait until the IRS asks before you send anything.

What if my child was born outside the United States?

You still need a birth certificate and Social Security number. If the birth certificate is from another country, you can use it — the IRS accepts foreign birth certificates. The child must have a U.S. Social Security number to be claimed, so apply for one as soon as you can. A passport or visa can also prove identity if you do not have the birth certificate yet.

How far back can the IRS ask for documents?

The IRS can ask for documents from the year you claimed the child, usually within three years of filing. If it suspects fraud, it can go back further — sometimes six or seven years. Keep documents for at least three years, and longer if you can, just in case.