Если для 1-го страничного заказа, то это шаблон order-opc-new-account.tpl, там нужно прятать 2 блока
<div class="checkbox" style="display: none;">
<label for="invoice_address">
<input type="checkbox" name="invoice_address" id="invoice_address"{if (isset($smarty.post.invoice_address) && $smarty.post.invoice_address) || (isset($guestInformations) && isset($guestInformations.invoice_address) && $guestInformations.invoice_address)} checked="checked"{/if} autocomplete="off"/>
{l s='Please use another address for invoice'}
</label>
</div>
<div id="opc_invoice_address" class="is_customer_param" style="display: none;">