More than 1.6 million British Columbian voters cast ballots in the Harmonized Sales Tax referendum, according to early numbers released Thursday by Elections BC.

That's roughly the same number who voted in the 2009 provincial election. In comparison, the mail-in 2002 Treaty Negotiations Referendum saw less than 800,000 ballots returned.

Elections BC says there were roughly 3 million registered voters in the province as of July 22, 2011.

Both the referendum deadline and deadline to request a voting package were extended to compensate for a Canada Post service disruption in June.

Acting Chief Electoral Officer Craig James said the extension cost roughly $500,000, but that the estimated overall cost of the referendum was only $8.9 million, or about $3 million less than expected.

The call centre set up to handle calls about missing or incomplete ballots received 87,617 phone calls since packages were mailed out on June 13.

Referendum results are expected to be released around Aug. 25.