4 main reasons why sanctions are used:

• Supress Terrorist Financing
• Change in Behaviour comportamento of a country or regime
• Apply Pressure pressure to a country or regime
• Enforcement Tool as an enforcement tool where international security has been threatened and diplomatic efforts have failed

in 2007 HM Treasury in responsible for administration of Financial Sections in UK, maintains a list of target relating to current United Nationals European Union

The UK sanctions regime applies to any person or firm within the UK and breathes can result in imprisonment and/or a fine.
Firms should have regard to the Treasury's sanctions list otherwise they may run the risk of breaching sanctions legislation and committing an offence of non-disclosure.

If you did identify one of your customers being on the financial sanctions list, you must immediately report it using your firm's internal reporting procedures.