Are there APIs available for insert and update Third Party and Third Party Site Tax Profile?

Client has huge volume of European Customers in the current 11i environment.  Currently they store the VAT registration number in a custom table to support the EU tax requirement.  They are reviewing the feasibility to migrate the VAT registration number using standard eBusiness Tax functionality. 

Are there APIs available for insert and update Third Party and Third Party Site Tax Profile to help them with the data migration?  If not, are there other options?

Thanks for your prompt attention.

Best regards,

Christine