Hi Abbas,
If you have to create the master data for these customers, I would rather suggest you to have a suspense BP created for the same.
Under this Suspense BP, you can create the Contarct Accounts, with a seperate Contarct Account category or number range so that it can beidentfied by naked eye.
And then you can post the charges against these customers.
This data model will ensure that all the accounts are collated under one BP and will be managable from a reporting prespective.
Hope it helps...
Thanks,
Amlan