Message type: E = Error
Message class:  FIRU_IMPRTCSTMSDECLN - Message class for Import Customs Declaration 
Message number: 703
Message text: Material Document &1 already used in Import Customs Declaration &2
Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.
To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.
Unfortunately, there isn't any extra information in this error notice.
First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).
Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.
You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.
The SAP error message FIRU_IMPRTCSTMSDECLN703 indicates that a material document (identified by &1) is already associated with an import customs declaration (identified by &2). This typically occurs in the context of customs processing within the SAP system, particularly when dealing with import transactions.
Cause: Duplicate Entry: The material document has already been linked to a customs declaration, and the system does not allow the same document to be used in multiple declarations. Incorrect Processing Sequence: The user may be attempting to process a material document that has already been processed or is in use in another transaction. Data Integrity: The system is designed to maintain data integrity and prevent conflicts that could arise from reusing the same document in multiple customs declarations.
Solution: Check Existing Declarations: Verify if the material document is indeed linked to another customs declaration. You can do this by checking the customs declaration records in the system. Use a Different Document: If the
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
FIRU_IMPRTCSTMSDECLN702 Purchase Order &1 already used in Import Customs Declaration &2
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
FIRU_IMPRTCSTMSDECLN701 No authorization to perform action for Supplier &
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
FIRU_IMPRTCSTMSDECLN704 Inbound Delivery &1 already used in Import Customs Declaration &2
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
FIRU_OFFS_ACCOUNT001 Account & does not exist in chart of accounts &
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
Click on this link to search all SAP messages.