OTTAWA -- An internal government audit has found that the federal government could save $7 million a year by giving new Canadians a social insurance number when they apply for permanent residence documents.

The idea auditors pushed would take two pilot projects that help new landed immigrants apply for social insurance numbers and expand them nationwide to more easily process hundreds of thousands of applications a year.

The process is similar to the way the government assigns newborn Canadians a social insurance number by doing so through the provinces when a birth certificate is registered, a program dubbed "SIN Birth."

That system in Ontario, for instance, cost $5 million to set up.

The audit, publicly posted late last month, suggests a similar system for new Canadians would cost about the same.

The department responsible, Employment and Social Development Canada, says it is studying the idea and a decision about whether to move ahead should be made by November.

Aside from the savings, the auditors who reviewed the social insurance number program said a one-stop shop for new Canadians to apply for citizenship documents along with a SIN would limit the chances for mistakes.

But the information used for those citizenship documents needs to be sound, and the audit suggests there remain a few opportunities for errors that could cost the government money or be an annoyance to a social insurance number holder.

Among those opportunities, the audit said, were the databases that Citizenship and Immigration Canada uses for permanent resident applications and as part of pilot projects in Toronto and Montreal, known as "SIN Landing" and "Mass Landing" respectively, where officials issue social insurance numbers to new permanent residents.

Auditors wrote the pilot projects are "beneficial from a client service perspective," but they don't provide the same savings "nor enhanced data accuracy opportunities" that the "SIN Birth" model can provide.

The federal auditor general report on Tuesday uncovered instances of people with serious criminal records and others with potentially phoney addresses securing Canadian citizenship.

The government auditors reviewing the social insurance number system raised concerns about the data provinces use for the SIN Birth program.

The audit says provinces haven't reviewed the accuracy of the data used for the SIN Birth program in the last 10 years, even though they are required to provide the results to Employment and Social Development Canada. Neither has the department asked for such reviews, auditors wrote.

A minuscule number of errors in the social insurance registry uncovered in the internal audit cost the government extra money in wrongful payments -- a mistake on a date of birth leading to extra payments of benefits, for instance. The majority of errors are annoyances that could lead to delays for people accessing government programs and increase government costs, auditors wrote.

Auditors also raised privacy concerns, including a lack of controls to track what social insurance numbers federal workers look up.

The department said access to the registry of social insurance numbers is strictly monitored. Department spokesman Josh Bueckert said in an email that access is only given to those who need it as part of their job, and those workers have to notify the department when that need changes.