Do I need to use my US company registration number?

Our UK clients are accustomed to legal requirements relating to the use of their UK company registration number (or CRN). They are therefore often surprised to learn that the registration number assigned to a US company is of very little significance in the US.

Firstly, an overview of the use of a CRN in the UK. When a company is formed in the UK, Companies House assigns a CRN as that company’s unique identifier. Thereafter, the CRN is used on such things as legal documents, correspondence with governmental bodies, and applications for licenses and permits. In addition, The Companies (Trading Disclosures) Regulations 2008 require that the CRN be used on a Company’s: (a) business letters; (b) order forms; and (c) websites.

Because there is only one company registrar in the UK, it makes sense that the CRN would play such an important role in the life of a company. But in the US every state plus the District of Columbia has its own registrar. Thus, there are 51 different registrars, each with their own numbering system.

Consequently, the company number assigned to a US company is of significance only in dealing with government agencies in the state that assigned that number. A US company does not use its registration number on letters, order forms, or websites. In fact, it’s almost never used except in annual filings required by the state of issuance.

Of far greater importance in the life of a US company is the EIN (also known as the “employer identification number” or “federal employer identification number”). This number is assigned by the IRS and is frequently used in dealing with government agencies at all levels. Occasionally, it is also placed on invoices sent to customers, although this is not legally required.