It has been an unrelenting slog for banks over the past six months but with a key deadline fast approaching, they had little choice.
The effort has involved updating IT systems, training staff and scouring through client accounts, all geared towards getting ready for a landmark new law that takes effect on Monday.
It has been hard work - the biggest such operation they have had to undergo in years - but the banks say they are ready.
The big change centres on one of the hottest issues in finance today: tax dodging.
The new law designates that tax crimes will be known as money laundering predicate offences, adding to other predicate offences including corruption, bribery and fraud.
A money laundering predicate offence is the underlying criminal activity that results in "dirty" money that might then be laundered.
The new law makes it harder for tax cheats to hide their ill-gotten funds in Singapore, as banks will now have processes in place to spot and root them out. Bank staff have now been trained to spot suspicious transactions and activities that look like tax evasion.
This is just one of several recent moves Singapore has made to get tougher on tax cheats.