Question on Vendor record being used by multiple companies

Hi Community

We have a situation where a vendor will be shared between 2 companies .Invoices from the vendor to one of the companies are tax exempt. As only one tax rate can be set up to default into the entry the tax rate will have to be set to exempt  when entries are being made to the other company if the vendor is set up for the company which is charged taxes.  Is it better to set up the vendor twice , once for each company as there is the impact to the tax file to be considered?

thanks for answers