SQL Database Design In Changing Business Environment

I am running an application with an SQL database and it works fine. My question is about a customer changing his information. We will need to be able to produce copies of old orders/invoices even after that company's info has changed (e.g. he moved or changed the company's name).

Assuming he changes his company's name, for example, do I,

1. Enter him as a "new" company? This allows me to keep the old info in the database if I query the "old" name but does not provide any portability of "old" information forward to the "new" company like payment patterns, past orders, etc. since he is "new" and has no past.

2. Or do I change the record of the"old" company to reflect the "new" name? Here I can keep the "old" past under the "new" name but I now cannot retrieve an old document that reflects the "old" name.

3. Or, the third alternative is to export to alternative storage all the files of the "old" company and go to number 2 above?

I thought about copying the "old past" into a "new" customer but then I'd have double sales, receipts, etc and I just can't see an end to that debacle.

None of these sound like fun but I'm sure I'll soon have to do one of these. I can't be the first one to ask this and I'm sure there is someone out there who is smarter than me/has a more elegant solution. Any suggestions?

I also posted this to Small Business Development forum but thought the SQL guys might have another idea.