Seven out of 10 consumers reported a reduction in the number of unwanted marketing messages after the launch of the Do Not Call Registry in January.
This was the finding of a poll of 1,000 consumers carried out in March by the Personal Data Protection Commission, which administers the Registry.
So far, more than 600,000 phone numbers have been listed on the Registry. More than three-quarters of the consumers who had their numbers listed have blocked all calls, text messages and faxes. The rest have blocked one or two of these.
Since the beginning of the year, the Commission has received 3,700 valid complaints from the public about receiving messages after they had registered their numbers.
Commissioner Mr Leong Keng Thai said: "While there were a few recalcitrant cases, we are pleased that most of the organisations we approached during investigation were cooperative and took prompt steps to correct their practices."