To convert MAS 90 data to QuickBooks, you can either do it yourself or use a professional data conversion service.

To do it yourself:

Export your data from MAS 90 in a format that is compatible with QuickBooks, such as CSV.
Clean and prepare your data for conversion. This may involve removing duplicate entries, correcting errors, and formatting the data to meet QuickBooks requirements.
Import your data into QuickBooks.

To use a professional data conversion service:

Choose a reputable data conversion service provider.
Provide the service provider with your MAS 90 data file.
The service provider will convert your data to QuickBooks and provide you with the new QuickBooks company file.

Here are some tips for converting MAS 90 data to QuickBooks:

Make sure that you have a backup of your MAS 90 data before you start the conversion process.
Clean and prepare your data for conversion before you import it into QuickBooks. This will help to ensure a smooth and successful conversion.
If you are using a professional data conversion service, be sure to choose a reputable provider.
Test the converted data thoroughly before you start using it in QuickBooks.