Managing Recurring Transactions from Service Contracts 
You can relate recurring transactions and service contracts. This may be valuable, for example, if you agreed to provide your customer with a certain service on a monthly basis and want to invoice the customer regularly.
Procedure
Linking Recurring Templates to Service Contracts
From the SAP Business One Main Menu, choose
Service 
Service Contract 
and open the relevant service contract.Select the Sales Data tab.
Under Recurring Templates in the Template column, choose a recurring template that has been defined for the customer or create a new one.
In the Service Contract window, choose Update and OK.
Executing Recurring Transactions from Service Contracts
Prerequisite: A recurring template has been linked to the service contract, as described above.
From the SAP Business One Main Menu, choose
Service Service Contract and open the relevant service contract.Select the Sales Data tab.
To display the recurring transaction instances related to the template that is linked to the service contract, set the check mark to the left of the template.
Under Recurring Transactions, all instances of the recurring transaction are displayed along with the status, execution date, and document total.
To execute a recurring transaction, click the yellow arrow related to a transaction.
The relevant document draft appears.
If necessary, change the draft, and choose Add.