Show the purchaser's phone number in the Tickets attendee list.

show-phone-number-attendees-list.php

if ( function_exists( 'tribe_is_event') ) {
	/**
	 * Adds the phone number to the "Purchaser Email" column.
	 * @link http://theeventscalendar.com/support/forums/topic/add-attendee-telephone-number-to-attendee-list/
	 */
	function tribe_953653_add_phone_to_attendee_list( $value, $item, $column ) {

		// Change this column name to move the phone number to a different column.
		if ( 'purchaser_email' != $column ) {
			return $value;
		}

		$phone_number = get_post_meta( $item['order_id'], '_billing_phone', true );

		// Remove the <small></small> tags from this to have the phone number text display at full size.
		if ( ! empty( $phone_number ) ) {
			return $value . sprintf( '<br><small><b>Phone:</b> %s</small>', sanitize_text_field( $phone_number ) );
		}

		return $value;
	}

	add_filter( 'tribe_events_tickets_attendees_table_column', 'tribe_953653_add_phone_to_attendee_list', 10, 3 );
}