She used twink on the certificates then paid two people to modify them further.
With the false identities she set up bank accounts into which a total of just over $222,000 was paid.
A summary of facts revealed O'Connor used the identities of three women living in Australia to get Working for Families tax credits and accessed the department's computer system to get information on 13 men and 11 child support customers whose tax credits and refunds were diverted back to the two bank accounts.
In all, the IRD paid $128,242.96 to one of her accounts and $93,989.76 into the other between June 2007 and November 2010. Work and Income NZ also made deposits of $3084.07 into one account.
The IRD began investigating her almost a year after she was made redundant when a customer told them that an incorrect bank account was associated with her account.
By then, O'Connor had spent much of the cash on cars for herself and her daughter. She bought electronic goods, groceries and spent on pokie machines.
Judge Glen Marshall said the scale of her offending was large but he took into account her poor health, her previously clean record, good character and early guilty plea.
But he questioned her remorse, particularly as key facts in a story about intimidation by gang members, who she claimed wanted $100,000 from her for a lost package, appeared to change over the course of a number of interviews.
"The [explanation] seems somewhat hollow and fanciful and my view is it is an attempt to cover up the fact that your gambling had become such a problem ..."
The IRD is seeking a return of the stolen money plus interest, penalties and costs for a total of $362,000.
EXTENT OF OFFENDING
Charges:
Corrupt use of official information: 24 charges
Dishonestly taking a document: 3 charges
Obtaining by deception: 17 charges
Accessing computer system for dishonest purpose: 27 charges
Forgery: 46 charges
Using forged documents: 46 charges
Funds received under bogus pretences: $222,232 from the Inland Revenue Department, $3084 from Work and Income New Zealand
What the IRD wants back:
$362,000 (includes interest, penalties and costs)