With the 1000 public tickets now gone, demand for seats at the drumhead service, which will take place at Edinburgh Castle's esplanade on August 10, is so high that there are plans to find room for 300 more members of the public, with free tickets hopefully made available in the coming days.
Tomorrow marks the official beginning of the First World War when Austro-Hungary declared war on Serbia.
In total, a congregation of around 9000 will be part of the service - including the 1000 members of the public already ticketed, and the rest of the congregation made up of ex-service personnel and dignitaries.
The drumhead service kicks off a four-and-a-half year programme of remembrance and commemmoration throughout the country with the 100th anniversary of Britain's entry into the war the first in a series of significant events to be marked.
It comes a week after the official centenary date of Britain's entry into the war - August 4 - when other commemoration events will take place throughout Scotland.
The dates that have been earmarked for remembrance as part of the official programme range from the outbreak of the war, to the May 1915 train crash near Gretna in which 214 officers and men died, and the Battle of Arras in 1917, when 44 Scottish battalions and seven Scottish-named Canadian battalions led an assault in the largest concentration of Scots to have fought together during the war suffering huge casualties.
The programme will run beyond the 100th anniversary of Armistice Day in 2018, with the loss of HMY Iolaire, which struck rocks half a mile from Stornoway on New Year's Day 1919 while returning home to Lewis with the loss of 204 of the 285 naval personnel aboard, the final episode of the war to be commemorated.
The drumhead service, which will be attended by VIPs and veterans from across Scotland, will recreate the church services held on the frontlines, where drums would be piled high to create a makeshift altar. It is intended to represent the moment before battle.
However, those who are unable to secure tickets to the event have been encouraged to travel to Edinburgh to mark the occasion. Following the service, there will be a procession down the capital's Royal Mile, representing the "march to war" and approach to the frontlines, which will arrive at Holyrood Park.
At Holyrood Park, there will be a replica Commonwealth war graves cemetery with headstones to represent the names recorded in the Rolls of Honour at the Scottish National War Memorial, to represent the scale of the loss of life as a result of the conflict.
Former Army chaplain Norman Drummond has chaired an expert group, which has met every six weeks for the last 18 months after being set up by the Scottish Government, to discuss the commemoration programme and make recommendations to ministers. He described the interest in the event, carefully planned by the 13-person World War One Commemorations Panel, as "tremendous".
He explained that the tagline for the series of commemorations, 'what do we learn from all this?', had resonated strongly across the generations and that despite the passing of a century, people of all ages still felt a strong emotional connection to the events of the Great War.
"The First World War has a resonance to our world today," he said. "The world was never the same after the First World War, and so many things that have happened since can be attributed to some aspect of it.
"We hope that in 25 or 50 years, people will look back and say they were there, they remembered, and they learned from the centenary commemorations of the First World War."
The drumhead service will follow an event in Glasgow, a week tomorrow, which follows the conclusion of the Commonwealth Games. Heads of state from competing nations have been invited to stay on in Scotland for the service, which will be attended by Prince Charles.
A special service at Glasgow Cathedral will be followed by a wreath laying event at the city's cenotaph, the day after the Glasgow 2014 closing ceremony. It has been billed as the focal point of the UK's and the Commonwealth's activities to mark the centenary.
But according to Drummond, the showpiece events represent only a small snapshot of a hive of activity to remember the First World War, which is to take place throughout the country.
It includes a First World War time capsule, which was put together by postal workers in Dundee and has been sealed shut since 1921. It bears a plaque saying it should be opened by the postmaster in the presence of the Lord Provost on August 4, 2014.
Drummond adds that he had accepted the request to chair the panel on the condition that three main principles - education, genealogy and legacy - were adopted.
Explaining the approach of the panel, which also includes Brigadier David Allfrey, a former Commander of The Royal Scots Dragoon Guards and producer of the Royal Edinburgh Tattoo, and Professor Louise Richardson, principal and vice-chancellor of the University of St Andrews, Drummond said: "It's certainly not a celebration of war or conflict. It's about asking how we can do better in our generation, and learning from the example of people who gave their lives in a very different time. We are keen to cover as many aspects of the war as can be achieved, warts and all. If things are difficult to reflect on, they should be included.
"There is the courage, compassion, duty and diligence but also the desperation in terms of the human element. People of all generations can readily identify with it when they hear that not many weeks after the declaration of war, people were setting off to conflict."
Culture Secretary Fiona Hyslop said it was important that across Scotland, there was the opportunity to recognise the significance and impact the Great War had on the country.
"Little more than 100 years ago nobody could have known the tragedy that was to affect every town, village, community and family in Scotland - claiming the lives of more than 100,000 Scots, leaving many more injured or disabled and forcing their loved ones to come to terms with the terrible consequences," she added.
"It is right that we remember that brutal conflict and reflect on how it shaped our society. Through the Scottish Commemorations Programme, we are inviting the whole of Scotland to join us on a five-year journey of learning and legacy."
A series of UK-wide events to mark the outbreak of the First World War will also take place in the coming weeks.
It is hoped that for an hour from 10pm on August 4, people across Britain will turn out their lights, replacing them with a single light or candle in a symbolic act of reflection and hope.
Britain entered the war at 11pm. At the same time as the event, a vigil is to be held at Westminster Abbey while The Houses of Parliament, Blackpool Illuminations, Old Trafford and Tower Bridge are among the landmarks taking part.
The Royal British Legion Scotland was set up to help servicemen and their families after World War One, and branches of the organisation have set up a series of their own events, such as a service in Stonehaven Square next Sunday and a candlelit vigil in Forfar on August 4. It will also be represented at the larger Glasgow and Edinburgh events.