Royal treatment: How Air NZ passengers can cash in on Meghan and Harry's big day

Prince Harry and Meghan Markle in the grounds of Kensington Palace in London. Photo / AP

Air New Zealand will celebrate the royal wedding of Prince Harry and Meghan Markle by offering free lounge access to passengers who share the same wedding date.

The offer applies to those travelling with the airline domestically and internationally on Saturday May 19. The airline is also serving special cocktails and cake at some of its lounges.

They do need to provide their marriage certificate showing they too were married on the 19th of May of any year to access any Air New Zealand operated lounge.

Air New Zealand manager global lounges Ali Swarbrick said the airline wanted to share the excitement of the royal wedding with customers.

"We look forward to rolling out the red carpet for customers travelling with us on Saturday and invite them to celebrate their own special day with us as we acknowledge the royal nuptials.

The airline will also serve celebratory Kir Royale cocktails in the Auckland International, Sydney, Los Angeles, Wellington domestic and Christchurch domestic lounges and is running a wedding cake competition.

The couple have chosen elderflower flavour for their wedding cake so customers in the Auckland International, Sydney, Los Angeles, Wellington domestic and Christchurch domestic lounges will be able to sample elderflower wedding cake made by the kitchen staff in each of these lounges as part of an in-house challenge.

British Airways has also wedding fever.

To celebrate the Royal wedding, the BA93 on May 19 to Toronto - the city where the couple's relationship took off - will be operated by an all-star crew of only Meghans and Harrys.

The 10-strong cabin crew, made up of two Harrys, seven Megans and one Meghan, departs an hour after the couple marry at Windsor Castle, 11km from the airport.

To celebrate the royal couple, any customer departing from Terminal 5 on the big day, who is called Harry, Meghan or Megan and their travel companions, will be invited to use the airline's First lounge, accessed through the exclusive First Wing.

BA is also doing some baking.

Lemon and elderflower Victoria sponges;will be given out to customers departing from Heathrow on the wedding day.

Extra champagne has also been loaded on to the Toronto celebration flight and the "Royal Crew" will give every customer on board a personal bottle of Castelnau Blanc du Blanc to enjoy alongside their individual celebratory wedding cake.