If your QuickBooks POS malfunctions—which is common when using modified files—you will be unable to contact official QuickBooks Support for help.
Merchants processing credit cards must maintain Payment Card Industry (PCI) compliance. Using unverified, modified software automatically voids your compliance, leaving you liable for fraud penalties and potentially revoking your ability to accept credit cards. How Official QuickBooks POS Activation Works
This is the most critical danger for your business. Intuit stopped releasing security patches for POS 18.0 after August 10th, 2021. Using an activator does not restore these security updates, leaving your system defenseless against cyberattacks, data theft, and other known vulnerabilities. Your entire customer database and payment information become a high-value target for hackers.