avatax.php

<?php 

add_filter('wc_avatax_order_origin_address', 'verde_change_avatax_order_origin_address', 10, 2 );
//	add_filter('wc_avatax_order_destination_address', 'verde_change_avatax_order_origin_address', 10, 2 );
	function verde_change_avatax_order_origin_address( $origin_address, $order ){
		
		$origin_address = array(); // empty saved address
		$branch_id = get_post_meta($order->id, '_avatax_branch_id', true);
		$branch_address = get_post_meta( $branch_id, 'wpsl_address', true );
		$branch_city = get_post_meta( $branch_id, 'wpsl_city', true );
		$branch_state = get_post_meta( $branch_id, 'wpsl_state', true );
		$branch_postcode = get_post_meta( $branch_id, 'wpsl_zip', true );
		$branch_country_iso = get_post_meta( $branch_id, 'wpsl_country_iso', true );
		$origin_address = array(
			'line1' => $branch_address,
			'city' => $branch_city,
			'region' => $branch_state,
			'postalCode' => $branch_postcode,
			'country' => $branch_country_iso,
		);
		return $origin_address;
	}
	
// change origin address at checkout	
add_filter('wc_avatax_checkout_origin_address', 'verde_change_avatax_checkout_origin_address', 10, 2 );
//	$origin_address = apply_filters( 'wc_avatax_checkout_origin_address', wc_avatax()->get_tax_handler()->get_origin_address(), $cart );
function verde_change_avatax_checkout_origin_address( $origin_address, $cart ){
    $origin_address = array(); // empty saved address
	$branch_id = WC()->session->get('branch_id');
    $branch_address = get_post_meta( $branch_id, 'wpsl_address', true );
    $branch_city = get_post_meta( $branch_id, 'wpsl_city', true );
    $branch_state = get_post_meta( $branch_id, 'wpsl_state', true );
    $branch_postcode = get_post_meta( $branch_id, 'wpsl_zip', true );
    $branch_country_iso = get_post_meta( $branch_id, 'wpsl_country_iso', true );
    $origin_address = array(
            'line1' => $branch_address,
            'city' => $branch_city,
            'region' => $branch_state,
            'postalCode' => $branch_postcode,
            'country' => $branch_country_iso,
            );
    return $origin_address;
}