TC

TC stands for

Economics

 * Trade Consistency

Social media

 * Tracking Code for Payment

Web analytics

 * Tracking Code for Web analytics tools based on the page tagging (like Google Analytics).

Word

 * Track Changes, when a document is drafted collaboratively

Other

 * Terms and Conditions, as in negotiations and contracts
 * Total Cost, an economics & cost accounting term
 * Total Communication, a form of Sign Language