Business owners who are behind in paying their taxes to the IRS are going to pony up more dough.

The IRS raised the interest rate on taxes past due to 6% for balances existing or beginning in the third quarter of 2008. That’s an interest rate increase of a full point (and reflects the fact that as more taxpayers join the self-employment sector, the government’s collection rate goes down as its collection costs go up).

It’s always tempting for a small business owner or self-employed business person to ‘take a loan’ from the ‘Bank of the IRS’ by deferring estimated tax payments or tax withholding — but it’s never a good idea, and it may constitute fraud or a criminal act. In addition to penalties and the monthly accrual of interest, the IRS has the absolute power to apply liens and levies and seize property and bank accounts.