No. Using automatic diallers for sales, telemarketing, and cold-calling campaigns is legal in most countries, including the US. However, many countries have strict regulations and laws around telemarketing practices, including auto diallers and robocalls. You must comply with these laws while using auto dialler apps, or it could lead to penalties.If your business is in the US, you must adhere to the Telephone Consumer Protection Act (TCPA) while using an auto dialler app. According to TCPA, you must have obtained prior consent from prospects before making calls using automated calling software. Furthermore, you must check the national Do Not Call (DNC) registry before using auto diallers. Check the complete laws here.Each state may also have individual laws around telemarketing practices. You must check and abide by the regulations in your country and the called party’s country before using an auto dialler app to avoid penalties.