There is only one file type that uses the .TTBK extension:
Canadian TurboTax 2010 Backup File
Backup of a tax return created with Intuit Canada TurboTax 2010; generated automatically when a .TT10 tax return file is saved; located in the same directory as the original file and has the same filename, except for the file extension.
TTBK files serve as backup copies of TT10 files. They can be used to restore a recently saved tax return if the original file is lost or corrupted.
NOTE: In order to open a TTBK file in TurboTax, you must change the file extension from ".ttbk" to ".tt10." Once you change the file extension, TurboTax will recognize and open the file.
|Intuit Canada TurboTax||Commercial|
Updated: August 1, 2011