The only reason you will need to re-register your company (ie obtain a new registration key) is if the Trading Name has been altered. Any other field of the company's details can be changed without needing a new registration key.
To change the company's details....
1. From the main screen of e-PayDay®, click on the 'Company' picture button
2. Highlight the company and click 'Edit'
3. At the bottom hand left of the screen click 'Edit Details'
4. Change any fields you wish
To produce company registration key form....
5. Click on the 'Register this Company' button at the bottom of the screen
6. A form will appear which you can print off and fax to e-PayDay Pty Ltd
To enter key in....
7. Once e-PayDay® have faxed or e-mailed the key back, place it in the Company Registration Key field up the top right
8. Click 'OK' to exit the Company Details screen