To create a house bank in sap you can use transaction code FI12 or path;
SAP easy access menu > Financial Accounting > General ledger accounting > Bank related accounting > bank accounts > Define house bank
Enter your company code in the initial house bank configuration screen and click on create house bank tab.
Enter all the details including your bank country and key used.
After filling up all the details click on ”bank account” and then click on create tab to create the account details.
Then double click on bank accounts and click on new entries to enter your bank account details.
Now SAVE it
Before creating it you should plan your general ledger account to be used in house bank. Generally more than one clearing accounts for different requirements like cheques clearing, wire outgoing are created.