You may get this message while installing Trend Micro Antivirus for Mac:

Invalid Serial Number

Why did this happen?

You may have used a different serial number or mistyped the serial number when activating the program.

How do I fix this?

Re-type your serial number
  1. Double-check the serial number:
    • Online Purchase: Find the 20-digit serial number on the Order Confirmation Email.
    • Retail Purchase: Look for the 20-digit serial number on the product box or on the receipt.
    • Existing Subscription: Log in to your Trend Micro Account to see the list of your ongoing licenses.
    Example format: AAAA-0000-0000-0000-0000.
    'A' represents a letter; '0' for a number.
  2. Enter the serial number, then click Continue.

    If it still persists, proceed to the next step.

Download the correct installer file

Serial numbers follow a different format for each program depending on how you acquired the serial number.