MiTime and MiTime Free v1.0.2 have been submitted to Apple for review. Both versions now include the option in Application Settings to customise the VAT label that is output on the invoice.
MiTime v1.0.2 also has a minor bug fixed where the invoice number output on the e-mail subject was one number higher that the actual invoice number created.
These features will become available once Apple has approved the updates and you have updated your version of the application.
You will not lose any data when you upgrade.