This is vital to ensure that you have the correct details for the business you are engaging with, that you know who within the organisation has authority to make payments, where you can escalate any concerns and your key contact within the business. You may also wish to take this opportunity to run a credit check against the company to understand their financial position before entering into a contract with them.
Over time, maintaining a positive relationship with the business and the key contacts will encourage prompt payment. By doing this, you will be kept up to date with any changes in people and management, allowing you to ensure invoices and contract matters are dealt with by the most appropriate person.