To become a copywriter, you'll need to earn a degree in English, communications or marketing and gain relevant experience to develop your writing skills and portfolio. An MBA or master's degree in marketing is recommended to advance to a leadership position or increase your earning potential. The first thing to do is write the copy for your own writing business. If you're going to be a freelance writer, you're a real business owner with a real need for effective texts.
Strictly speaking, copywriters don't need any formal qualifications, just the ability to write well and learn the tricks of the trade quickly.