According to media reports, British Defence HQ set such preparation as a mission of "highest priority," with only two months left before the 29 March 2019 deadline.
If negotiators on both sides of the Channel fail to reach an agreement, UK military chiefs may also recruit civil servants from the MoD and its other agencies to assist the government with potential disruption.
In a letter reportedly written by Stephen Lovegrove, the permanent secretary at the MoD, he has instructed the personnel on the measures required in case of a no-deal Brexit.
"However, moving into the New Year we will not only have to continue this hard work but treat it as our highest priority. If necessary, this will need to include delaying or deprioritising areas of work or reallocating internal resources to better meet no deal demands," he reportedly said back in December 2018.
As part of the cross-government no-deal contingency planning, codenamed Operation Yellowhammer, Westminster could call on soldiers set to respond to a military crisis overseas and redeploy them in Britain instead if the need arises.
In relation to the UK defence personnel working overseas, Westminster has previously called on the EU "to uphold their commitments to citizens and to protect the rights of UK nationals in the event of a ‘no deal' scenario."
In December 2018, the government issued an update for Service Personnel, their families and Defence based in the EU:
"The MOD understands that ongoing uncertainty causes concerns for some staff and their families overseas. The MOD, with the support of your chain of command and supporting organisations, is actively monitoring the situation and will keep you updated on the key developments likely to affect you and your family members. We are already looking at a range of matters that may affect our people when the UK leaves the EU. These include issues around travel, immigration, employment status of dependants, and education."
Training for the military staff in preparation for a no-deal strategy is set to start next month.