A letterhead is the heading at the top of a sheet of letter paper (stationery). That heading usually consists of a name and an address, and a logo or corporate, and sometimes a background pattern. The term "letterhead" is often used to refer to the whole sheet imprinted with such a heading.

The majority of company letterheads are printed A4 in size (210mm x 297mm) although occasionally A5 (148mm x 210mm) and other bespoke sizes are sometimes used. There are certain pieces of information that are required to be displayed by law. The company name must be included, the place of registration, the registered number and the address of the registered office. For example, if your company name is ABC your logo only shows part of the name then you must include the full registered name on the letterhead. There is no need to include the names of the directors on the letterhead, however, if you choose to name the directors, you must ensure all the directors are named.