When you claim Child Benefit, HMRC may ask you to confirm your identity and provide details such as your National Insurance number, address and date of birth. You might be asked for supporting documents, such as a passport or driving-licence details, but the exact checks depend on your circumstances and how you apply. If you cannot provide a document, contact HMRC, as alternative checks or evidence may be available. Check the latest requirements on GOV.UK before sending original documents.