I would probably just truncate it and not display an error. There has to be some reasonable limit, and this is the first time anyone has mentioned the 64 character limitation. I am curious what the name is (Or a pseudo of the name). Long company names are generally shortened for marketing purposes. I doubt they answer the phones "Good morning, you've reached the law offices of Ziffren, Brittenham, Branca, Fischer, Gilbert-Lurie, Stiffelman, Cook, Johnson, Lande & Wolf, how many I direct your call?"