Standard Cost estimate not found

Hi Friends,

We are trying to release a billing document to accounting. However, we are getting an error of "No std cost estimate could be found for material 616091" The long text shows that "No valid material cost estimate exists in plant PH98 for material 616091"

However, if we check the billing document, the plant which is maintained is PH81 and not PH98 (which is admin plant).

Please let us know how do we resolve this error.

Rgds,

Kunal