magento-test/app/code/Magento/Customer/etc/fieldset.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:DataObject/etc/fieldset.xsd">
    <scope id="global">
        <fieldset id="customer_account">
            <field name="prefix">
                <aspect name="create" />
                <aspect name="update" />
                <aspect name="name" />
            </field>
            <field name="firstname">
                <aspect name="create" />
                <aspect name="update" />
                <aspect name="name" />
            </field>
            <field name="middlename">
                <aspect name="create" />
                <aspect name="update" />
                <aspect name="name" />
            </field>
            <field name="lastname">
                <aspect name="create" />
                <aspect name="update" />
                <aspect name="name" />
            </field>
            <field name="suffix">
                <aspect name="create" />
                <aspect name="update" />
                <aspect name="name" />
            </field>
            <field name="email">
                <aspect name="create" />
                <aspect name="update" />
            </field>
            <field name="password">
                <aspect name="create" />
            </field>
            <field name="confirmation">
                <aspect name="create" />
            </field>
            <field name="dob">
                <aspect name="create" />
                <aspect name="update" />
            </field>
            <field name="taxvat">
                <aspect name="create" />
                <aspect name="update" />
            </field>
            <field name="gender">
                <aspect name="create" />
                <aspect name="update" />
            </field>
        </fieldset>
        <fieldset id="sales_convert_order_address">
            <field name="vat_id">
                <aspect name="to_quote_address" />
            </field>
            <field name="vat_is_valid">
                <aspect name="to_quote_address" />
            </field>
            <field name="vat_request_id">
                <aspect name="to_quote_address" />
            </field>
            <field name="vat_request_date">
                <aspect name="to_quote_address" />
            </field>
            <field name="vat_request_success">
                <aspect name="to_quote_address" />
            </field>
        </fieldset>
        <fieldset id="sales_convert_quote_address">
            <field name="vat_id">
                <aspect name="to_order_address" />
                <aspect name="to_customer_address" />
            </field>
            <field name="vat_is_valid">
                <aspect name="to_order_address" />
                <aspect name="to_customer_address" />
            </field>
            <field name="vat_request_id">
                <aspect name="to_order_address" />
                <aspect name="to_customer_address" />
            </field>
            <field name="vat_request_date">
                <aspect name="to_order_address" />
                <aspect name="to_customer_address" />
            </field>
            <field name="vat_request_success">
                <aspect name="to_order_address" />
                <aspect name="to_customer_address" />
            </field>
        </fieldset>
        <fieldset id="sales_copy_order_billing_address">
            <field name="vat_id">
                <aspect name="to_order" />
            </field>
            <field name="vat_is_valid">
                <aspect name="to_order" />
            </field>
            <field name="vat_request_id">
                <aspect name="to_order" />
            </field>
            <field name="vat_request_date">
                <aspect name="to_order" />
            </field>
            <field name="vat_request_success">
                <aspect name="to_order" />
            </field>
        </fieldset>
        <fieldset id="order_address">
            <field name="vat_id">
                <aspect name="to_customer_address" />
            </field>
            <field name="vat_is_valid">
                <aspect name="to_customer_address" />
            </field>
            <field name="vat_request_id">
                <aspect name="to_customer_address" />
            </field>
            <field name="vat_request_date">
                <aspect name="to_customer_address" />
            </field>
            <field name="vat_request_success">
                <aspect name="to_customer_address" />
            </field>
        </fieldset>
    </scope>
</config>