According to the IRS, if the day care provider is an individual, enter her Social Security number. If the provider is a day care facility, enter the Employer Identification Number. For tax-exempt day care organizations, such as churches or schools, enter "Tax Exempt" in the identifying space of IRS Form 2441. Ask the provider for the information directly or use Form W-10, Dependent Care Provider’s Identification and Certification, to request the required information from the day care provider.
If the day care provider refuses to give you the necessary identifying information, you may still claim the credit. Enter any information you have to identify the provider, including the name and address. You must attach a statement of due diligence to explain the steps you took to obtain the Social Security number or Employer Identification Number. In the space for the identification number, write "See Attached."