How does a marketing plan relate to an organization's communications plan? What are differences? Is marketing plan just one aspect of communications plan? Should one consider combining them into a single document?
A communications plan is a PART of your marketing plan. A communications plan is a focused strategy you use to get word out about your business, product or service.
You may use a variety of communications tactics such as public relations, advertising and speaking engagements. Yes, it does identify who you are communicating to and what your message is, and where and how you will get that message out, and often has goals or objectives you are trying to achieve.
Here's difference between two
A marketing plan starts by creating a strong, strategic marketing foundation for your communications plan. It addresses goals and objectives for your business, not just for your communications activities.
It addresses how you package, price and sell your product or service, not just how you talk about it. It takes into consideration your competitors and helps you develop a unique selling proposition to ensure your product or service is uniquely positioned in minds of your prospects and customers.