Advice on issuing invoices and carrying cash
Special attention must be paid when issuing invoices in cross-border transactions. The demands regarding information that must be contained in the invoices are much higher in some countries than in Great Britain.
Especially when trading with several dealers, if the demands are not adhered to, one can easily be accused of MTIC (missing trader intra-community) fraud.
One must be extremely careful when carrying cash into the country. Apparently sniffer dogs are used in English airports to find cash. The limit is 10,000 euros. Money is excess of this must be declared. But one should exercise caution here, too, as the declaration may lead to further unpleasant questioning.