Yes, that’s exactly right.
You can get Form W-10 here. You'll need to fill it out and send it to your provider, using certified mail, receipt requested. Be sure to make two copies of this form for your own records. If you don't receive a response within a reasonable amount of time, you should go ahead and complete your return, leaving the provider's ID number blank on Form 2441.
Prepare a statement (outside of TurboTax) explaining your due diligence. Print your return and attach the statement to the back of the return, then mail your return. You won’t be able to e-file your return without your provider’s EIN or SSN.
According to Due Diligence on page 3 of the IRS' Instructions for Form 2441, "You can show a serious and earnest effort (due diligence) to get the information by keeping in your records a Form W-10 completed by the care provider. Or you may keep one of the other sources of information listed in the instructions for Form W-10. If the provider doesn't give you the information, complete the entries you can on line 1. For example, enter the provider's name and address. Enter “See Attached Statement” in the columns for which you don't have the information. Then, attach a statement to your return explaining that the provider didn't give you the information you requested."
Unfortunately, you can't attach a statement to an e-filed return, so you'll need to print and mail your return to be able to claim the credit.
Please see the TurboTax Help articles How do I print and mail my return in TurboTax Online? or How do I print and mail a return in the TurboTax for Windows CD/Download software? as appropriate for the instructions on filing your return by mail.
