They host their French counterparts in the third and final game of a three-team round robin tournament - also involving the Dutch - on Friday evening (7pm). There is free admission for everyone.
It is a winner takes all clash as both teams have so far beaten the Dutch - the UK winning 3-1 at Westleigh Park on Monday and the French caning them 4-0 last night.
With the French currently leading on goal difference, the UK have to win in order to be crowned champions of a tournament that started in 1921.
The Kentish Cup is officially recognised by UEFA as the longest-running tournament in European football.
It is named after Brigadier General Reggie Kentish - a former vice chair of the British Olympic Association - and was first played for 101 years ago with the purpose of fostering relations between Armed Forces.
For many years, the British Army played against the French and the Belgian Forces, but in 1980 the Army handed the competition to the Combined Services FA.
That was because conscription was still introduced in the Belgian Armed Forces and the level of players available to them included international standard players.
When France withdrew in 1986, they were replaced by the Dutch. But when the Belgians pulled out in 2005, the French returned.
Two members of the UK Forces squad are no strangers to Westleigh Park. For goalkeeper Luke Cairney and defender Keith Emmerson both played there earlier this year for Hungerford Town against the Hawks in a National League South fixture.
It was an eventful evening for both players - Cairney was forced off injured in the second half with Emmerson, a centre half, taking over in goal due to a lack of a substitute shot-stopper. Hungerford eventually lost 4-0.
Both players have since left Hungerford and signed for south coast Southern League Premier clubs - Cairney for Poole Town and Emmerson for Dorchester Town.
Prior to this week’s tournament, all competing players were given a message from Prince William, the Duke of Cambridge.
Writing in the official programme, he said: ‘Football has a remarkable ability to bring nations together and to build trust, respect, and positive relationships. For the last 100 years the Kentish Cup has achieved this, and I pass on my personal congratulations to all those involved in this important competition for achieving such a significant milestone.
‘My very best wishes to the players, coaches and officials of the United Kingdom, France, and The Netherlands for this year's Kentish Cup. May the best team win!’