Royal invite for tiffin carriers
Raghunath Medge and Sopan Mare are two of the dabbawallahs who pooled money a few weeks ago to send Charles and wife-to-be Camilla Parker Bowles gifts.
Prince Charles met the tiffin carriers on his trip to India two years ago.
Mumbai has an estimated 5,000 tiffin carriers delivering about 175,000 lunch boxes daily in a century-old tradition.
Mr Medge, president of the Bombay Tiffin Box Supply Charity Trust, which represents the dabbawallahs, said the expenses-paid invitation was a "dream come true".
"It is a noble gesture on his part as we are poor, hard-working people and never ever imagined to be part of such a grand royal wedding," Mr Medge told the AFP news agency.
"We are on our way to the British High Commission for our visas and are looking forward to an exciting week."
The dabbawallahs had sent wedding gifts that included a traditional Indian headdress for Prince Charles and a sari, blouse and bangles for Camilla.
Mr Medge said he and his colleague were planning to take some more gifts for the prince and his bride.
The dabbawallahs collect tiffin boxes from suburban homes and deliver them at their offices and factories at lunchtime.
"Tiffin" is an old English word meaning midday snack.
A unique tracking system ensures that all the lunch boxes reach their rightful owners in time, earning a rating of 99.99% for precision and accuracy from Forbes magazine.
That's one error in 10,000 deliveries.
The tiffin carriers say that they can never forget their meeting with the Prince of Wales.
"It was because of his visit that people around the world came to know about our work. For the first time in our 114-year history, our achievements were noticed," said Mr Medge.
"Prince Charles gave us so much importance. He chose to meet us instead of the high-profile people."
The vocation of supplying tiffin in Mumbai began in 1890, when the British and Parsi communities in the city needed convenience lunches.