Cross-Company and other plant

Dear All,

We have three compnay codes 1000, 2000 and 3000. And we have cross-company scenario between 1000 and 2000 which is working fine.

We have also created vendors 1000 and 2000 in the system.

Now company 3000 is going to procure some materials from company 1000, but we have not customized cross-company as our client didn't want to.

When i try to create a PO to vendor 1000 for company 3000, system gives error messages like "material is not created for delivering plant 1000"

So what i understand is that, we need to customize cross-company for 1000 and 3000 as well.. or .. we need to create another vendor code for company 1000 which has no delivering plant assigned.

Is the any other option ?

Thanks in advance.

Best regards,