The state Department of Taxation said it is updating its Web site to make it easier for taxpayers to complete the general excise periodic tax form online.

Starting Jan. 5 taxpayers who fill out Form G-45 will find that the new version will perform the math calculation for taxpayers who fill out the form electronically, or use the "Web-fillable" version of the form.

The tax department said the new feature eliminates about 90 percent of the errors made by taxpayers.

To fill out the form electronically, go to www.hawaii.gov/tax and click on "E-Services." Users will need to register to use the service. Once completed, the form can be filed electronically immediately.

To complete the Web-fillable form, go to www.hawaii.gov/tax and click on "Forms." Next click on "Alphabetical List," then the letter "G," and scroll down to the Form G-45 entry and click on "General Excise/Use Tax Return (Rev. 2008 - Calculated). Once completed, the Web-fillable form can be printed out and mailed in.