When I access my account, I can't see the option to fill in the profile questionnaire requested by my customer.

There are two possible reasons why you might not see the Customer Requested tab in your Company Profile:

1. Your account is not linked to any Sourcing customer. To resolve this, you can link your account to a Sourcing customer by using the event invitation sent to your email address. See How do I register on SAP Ariba Sourcing? for more information.
   
   Once your buyer is linked to your account, the Customer Requested tab will appear, and any questionnaire your customer created will be available there. If you have not received an invitation, check with your customer to see if they have a link for self-registration.
   
   
2. You are using a sub-user account without the necessary permissions. To resolve this, ask your account administrator to change your account roles and grant you the Customer Administration permission.

SAP Business Network for Procurement & Supply Chain > Administration (Buyer & Supplier Account Administration) > Company profile
Supplier Lifecycle & Performance > SM Administration