How can I disable the integrated QuickBooks merchant service ?
QuickBooks POS version 10 and below:
In the Company Preferences | Merchant and Gift Services, please remove the Merchant number.
Newer QuickBooks POS versions (i.e 2013 or newer):
Choose File > Setup Interview. Click the Payments tab. Select No and then click Done.
Other QuickBooks versions (Pro, Premiere, Enterprise):
Make sure the checkbox 'Process ... credit card payment' is unchecked all the time when you save a sales receipt, a receive payment or a credit memo..