Is it possible to set the taxvat field as not modifiable on the customer panel in frontend?

[carlo_antonelli]

There is a way to set the tax vat field in the customer account panel as not modifiable?

I need that the customers have to request the change directly to the admin, and cannot modify the field in the frontend.

Thank you.

[carlo_antonelli]

I haven't clarified enough the problem. When a customer register on the site the tax/vat filed number is required. After the registration when a customer login on the personal account panel magento gives the opportunity to change that tax/vat number. I need to block this possibility.