Answer
Once you have paid for your subscription — whether monthly or annual — you will receive an invoice to your registered email address along with a new subscription ID.
Desktop App: To enter the new subscription details into the Lightning Payroll desktop program, go to Tools >> Licence Assistant >> Enter Registered Email Address >> Subscription ID >> Download Licence >> Install.
Once the install dialogue box disappears, you have successfully installed the new licence.
Web App: If you’re using the Lightning Payroll web app, your subscription will be picked up automatically when you log in — no need to enter a subscription ID.