Issue with Partner functions & Credit limit.

Dear Expert,

I have a doubt regarding partner functions, I want to say with an example.

Reliance is the company head quarter Delhi - > I created Reliance is Sold to party with credit limit 50 lac*.

Reliance Hyderabad,Mumbai,Chennai are the branches - > I created as ship to party.

case 1 : Sold to party:Reliance Delhi

Ship to party:Reliance Hyderabad

this case is clear.

case 2:Sold to party:Reliance Hyderabad

Ship to party:Reliance Hyderabad

How can i handle a situation with case 2.

Note:Credit limit needs to be maintained for complete Reliance Company(Head Quarters) Not to the branches.

Please suggest me.

Regards,

Siva Krishna