Barclays, HSBC, Lloyds, Santander, RBS and Nationwide are all on board.
Armed Forces posted overseas will be able to rent out their homes without switching mortgages and Barclays, HSBC, Lloyds, Santander, RBS and Nationwide are all on board.
The MoD and British Bankers Association said the move will benefit almost 265,000 people by saving them money and time.
BBA chief Anthony Browne said: “Members of our Armed Forces work all over the world to look after us, so it’s only right that we look after them.
“The extra support proposed by the banks and the Ministry of Defence will make sure service personnel and their families are not disadvantaged for working aboard and make their mortgages and credit history fairer.”
Banking chiefs and ministers met at 10 Downing Street today to discuss further measures to help service personnel and their families.
The financial services sector typically has difficulty recognising the postcodes of UK military bases abroad, while time spent abroad can affect the Forces community’s credit history. They can also lose out on claims bonuses and discounts with the insurance industry.
Defence secretary Michael Fallon said: “Looking after your home and your money can be more of a challenge when deployed on operations or serving abroad.
“This is a welcome first step from the major banks and financial institutions to help our servicemen and women get a better mortgage deal.
“I look forward to further pledges from across the financial services sector to support the Armed Forces Covenant after today’s roundtable.”
Barclays has allowed personnel to rent out their homes for many years and is expected to commit further measures after the meeting in Downing Street.
Ashok Vaswani, chief executive, personal and corporate banking, Barclays, said: “It should be a priority for banks to make sure that men and women who serve our country are not disadvantaged in any way as a consequence of their military service.
“We recognise the personal sacrifice made by our Armed Forces, so its right that our mortgage policy ensures they are not are penalised. Having had this in place for several years we are delighted to see other lenders now joining us.”
He added: “Barclays has already helped over 3,700 veterans through our AFTER employment transition programme and we are determined to do even more to meet the needs of military personnel and veterans by making our banking services more flexible, accessible and convenient.
“That is why I wholeheartedly welcome the government’s efforts and discussion around what more the banking industry can do as a whole to better serve our Armed Forces.”