Eugenie's strict dress code comes just days after it was announced how much her wedding was actually costing.
Security at Princess Eugenie and Jack Brooksbank’s wedding will cost a staggering £2 million (approx $3.4 million AUD).
The Mirror reports taxpayers will be forking out the amount for the wedding, adding extra firearms and police will be utilised.
The Mirror also claims dad Prince Andrew was said to have demanded a 'glitzy event' for his younger daughter.
A source said: 'The Duke of York has insisted his daughter’s wedding must be a huge occasion to be remembered and wants everyone to get on board to celebrate the happy couple.'
The Express claims Eugenie and Jack’s October 12 wedding could cost between $675,000 and $1.35 million.