Hamilton computer firm Elite Business Systems was temporarily flush with more than $4 million in additional funds this week.
The company received a Westpac fax telling them $4.3 million had been transferred into its account on behalf of a client paying a bill.
Administration manager Graeme Richer couldn't believe his eyes because the sum owed was just $43,000.
"We were hopeful, almost had our tickets booked to fly out to Hong Kong," he told The Waikato Times.
The mistake, which Westpac spokesman Craig Dowling said was "a simple typing error", had been corrected.
Last month, Rotorua couple Leo Gao and Kara Hurring skipped the country for Hong Kong after Westpac mistakenly put $10 million into Mr Gao's account.
Mr Gao had asked for a $100,000 overdraft.
Westpac said most of the money had been recovered but $3.8 million was still outstanding.
Police are seeking the help of Chinese authorities to find the pair.
