If you're in the business-to-business market, you already know that the best time to find new prospects is before they have signed a contract with someone else. Getting to them after they have opened their doors is often too late. Fortunately, there are plenty of ways to find out who is planning on opening a business weeks or sometimes months before the business officially sets up shop.

How to find new businesses opening in your area will likely vary depending on where you are located, but a combination of any of these methods should give you a good head start.

Look at Public Records

Before starting a business, companies must register with their state, county or municipality as a business entity. These local business registrations are a matter of public record. Contact your local tax assessor's office or your state or county public records office to find out how you can access these records.

A growing number of governments are making these records available online. If you live in New Jersey, for example, you can search for businesses by the date they were registered and by municipality.

If you live in a large city, this may not be the most efficient way to search for new businesses since thousands may register in a given year, and their names may not always tell you what they plan to do. It's also the case that many people register a business but never actually get that business off the ground.

Read the Local Newspaper

Your local newspaper provides a wealth of information for businesses. The local business section often has stories on new businesses that are published long before the official opening, particularly if that business is going to be paying for ads after it opens.

Newspapers also include public notices about proposed zoning changes. Keep a look out for any properties that may be changed to industrial or commercial. Somebody is most likely planning to open a business there.

In some states, if a business wants to operate under a different name than its legal entity name, known as "doing business as," or DBA, the business must place an ad in the local newspaper's public notices section stating the DBA name and the company's name.

Look for Local Jobs

While you're scanning the newspaper, check out the Help Wanted section. Look for jobs in your community that relate to the businesses with which you interact. Except for mom and pop shops, if a business plans to open its doors in the near future, it will need an employee or a manager there to turn the handle.

If you work with retail stores, look for store manager and retail sales positions being posted and look at the company posting those ads. For other businesses, sales reps, office managers and receptionists would be some of the positions to be filled before the company officially opens.

How to Find New Business Listings on the Internet

Keep an eye on Facebook, Twitter and LinkedIn for any posts about new businesses in your area. Each of these platforms gives you the opportunity to search for specific words like "opening soon" or "new business" along with the name of your town or city.

Google's news can also be a big help. By going to news.google.com, you can enter the keywords for which you're searching and then, at the bottom of the page, create an alert so that you will be notified immediately whenever an upcoming business makes the news or someone's blog post.

Look for location-based websites and social media groups that pride themselves in keeping people abreast of upcoming events in your area. Another site to check out is nextdoor.com, a location-based social media platform. Local businesses have the opportunity to create their own pages there, which they may do before they officially open their doors.

Network in Your Community

Business is always about people, so the more business people with whom you interact, the more likely you will hear about what's new in your area. Consider joining a local business association and get to know the people who are in the know. Bank managers, real estate agents and insurance agents will often know who is planning to open a new business before anyone else.

Check out meetup.com to see if there are local meetups for entrepreneurs or business owners in specific fields in which you are most interested. If there aren't any meetup groups related to the business people you want to meet, consider starting your own.