If the Costco TurboTax copy was an e-delivery, please check your email for the code or try this Troubleshooting article for help finding the License Code.
For those with the Disc purchased from Costco, it should be included in the packaging or on the disc:
If you obtained the TurboTax CD from an authorized retailer, your license code is printed on the front of the insert in your box.
If you obtained the TurboTax CD directly from TurboTax.com, your license code is printed on the packing slip.
If you obtained the TurboTax CD through TurboTax Advantage, your license code is printed on the envelope.
