The only possible TXF to T12 conversion known to us is importing a Tax Exchange Format file (*.txf) to At Home accounting software and produce a tax return file, such as the *.t12 that was used for year 2012.
Convert Tax Exchange Format to H&R Block At Home 2012 tax return file.
We found one software available in the database for this conversion.
Microsoft Windows software - convert txf to t12 on Windows
A popular tax preparation software from HRB Digital
Convert from txf file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.