Using the correct form of address avoids offending the woman.

The correct way to address a woman in writing if you don't know her marital status is to use "Ms." before you write her name. Although you might eventually learn if the woman is single, married or widowed, and have to change the way you address her in subsequent letters and emails, "Ms." is the universally acceptable way to address a woman with an unclear marital status.

Keep It Simple With "Ms."

Write "Ms." and the woman's given name and surname on the envelope if you're writing a letter or card to the woman. Begin your message with, "Dear Ms." and the woman's surname. This approach is relevant whether you're writing to someone in a personal setting or in a business context. To ensure you use the correct form of address, contact the woman or a friend or family member and inquire if she uses "Ms." or prefers "Mrs." or "Miss."