Find Matches in two different Spreadsheets without unique ID

Hi,

I have two worksheets. One has 50K+ data,extracted from one database, the second one has 400 records extracted from another database.
Both spreadsheets have Account Name, but spelling might be different- Company ABC and Company abc, Company A.B.A. ,for example.
There is no unique identifier. I need to compare these two spreadsheets to find matches need excel either highlight them or put in a different worksheet.

I'll have to do it fairly regular- comparison of two different set of data in order to find matches, unique ID won't be there. With all this said, maybe I need a macro or some process set up, which I can use in my future comparisons.
Any help is greatly appreciated!