For intra-Community transactions, Slovakian VAT invoices must be issued by the 15th day of the month after the taxable supply. For all other transactions, an invoice should be issued within 15 days of the taxable supply taking place. Invoices must be stored for ten years unless they relate to immovable property in which case they should be kept available for twenty years. Slovakia, like all EU member states, now permits the use of electronic invoices under certain conditions.