If you haven’t paid your property taxes for 2011, you’d better get that checkbook handy.

Technically, today is the last day you can pay without facing a delinquency fee or, worse, having your property placed in a tax certificate sale and a lien placed on the parcel.

But because March 31 falls on the weekend this year, the taxes – which were actually due by March 1 – can be paid in person or online through Monday without paying a penalty, according to Linda Baer, assistant director of customer support at the Lee County Tax Collector’s office.

“We will allow a March payment on Monday or online,” Baer said. “If you mail your payment, it must be postmarked by March 31.”

If the tax isn’t paid by then, the county assesses a 3 percent penalty and an advertising fee for putting your property up for the tax certificate sale, which is 70 cents, Baer said.

Tangible taxes, on properties owned by businesses (a restaurant owning an oven, for example) are assessed a 1.5 percent penalty and a 20 cent ad fee.

The delinquent properties are advertised once a week for three consecutive weeks, online and in the newspaper, prior to the sale, according to the Lee County Tax Collector Web site.

If taxes aren’t paid by May 1, a tax certificate sale commences. The sale is for the purchase of a lien for the delinquent taxes, interest, costs, and charges for the property in the certificate.

The sale is operated with interest bids beginning at 18 percent and progressing downward in .25 percent increments. The certificate goes to the bidder who accepts the lowest rate of interest, the Web site said.

“The bidders pay the taxes for the owners and earn interest on the money they pay,” Baer said. “They can hold onto the certificates for up to two years, they can then initiate a tax deed application that will result in the loss of the property if the taxes remain unpaid.”

The certificates have a life of seven years from the date of delinquency. If not redeemed, the certificate is null and void, and the holder will not receive a return on his investment, the Web site states.

Last year, 50,418 parcels were advertised, with 38,770 brought to the certificate bidding process and 38,724 sold. More than 17,000 were struck by the county, which means there were conditions on the property, such as Homestead Exemption and property taxes of less than $250.

By way of comparison, in 2006, only 30,931 parcels were advertised, with 19,484 brought to certificate sale. Lee County struck 81 in 2006, with none in 2007, as property values had peaked.

“Some of these properties don’t have mortgages and for those that do, some mortgage companies don’t offer escrow to pay taxes,” Baer said.