The District is offering delinquent taxpayers a one-time, last-chance opportunity to be forgiven -- but not totally absolved.

A new tax amnesty program will allow taxpayers who have outstanding tax liabilities with the District government to clear up their debts without civil or criminal penalties. Those who do not pay up, however, will face stiffer penalties later.

During the amnesty period, July 1 to Sept. 30, people who have underestimated or underreported their income, failed to pay taxes, or failed to file tax returns for any tax period before Nov. 1, 1986, can apply for amnesty and make restitution.

Under the program, all interest and penalties will be waived for those who apply and pay all back taxes on or before July 31. Those who apply and make payment between Aug. 1 and Sept. 30 will have all penalties waived and get a 50 percent reduction in interest due. The amnesty was mandated by D.C. Council legislation sponsored by John A. Wilson (D-Ward 2) in March. The measure drew objections from Mayor Marion Barry's administration and others, including questions about how much money it would raise for the city's coffers.

City officials said they expect to generate about $10 million in revenue from delinquent taxpayers during the amnesty period, out of a total of about $40 million in delinquent taxes.

Included in the program are the individual income tax, inheritance and estate tax, franchise tax and other business taxes. Residential and other property taxes, however, are not covered.

After Sept. 30, delinquents may face garnishment of wages and increased interest and penalties.