TurboTax only retains the current and past 7 tax years, the same retention period as the IRS.
The IRS provides tax transcripts for the past 10 years but the transcript will not include an EIN from your business - https://www.irs.gov/individuals/get-transcript
Go to this IRS website if you have lost or misplaced your EIN - https://www.irs.gov/businesses/small-businesses-self-employed/lost-or-misplaced-your-ein
