Banks have played a key role in the development of Guernsey as an international financial centre.

The first merchant bank was established in Guernsey in 1963. Today's licensed banks represent a range of countries with concentrations of banks with head offices in the UK and Switzerland.

The range of services offered by banks in Guernsey is quite diverse. Some provide retail banking services essential to the local community. Others target the affluent expatriate market, primarily attracting their deposits. There are also banks offering "private banking" services attracting high net worth individuals who seek a total wealth management solution to their financial needs. Banks also support the other financial services businesses operating in Guernsey providing custody, foreign exchange and other banking services to the investment, fund administration, fiduciary and insurance sectors. 

At the last third party review by the IMF in 2010, Guernsey was compliant or largely compliant in all the international core principles.