Thousands of Pennsylvanians who purchased cartons of cigarettes over the Internet or by mail order have been sent letters by the state Revenue Department informing them they owe taxes.

The first batch of letters went out about two weeks ago to 4,300 people who are believed to have purchased at least 100 cartons and collectively owe $10.4 million in taxes.More than 700 of them have already enrolled in a payment plan, the Revenue Department said.

The largest purchase was 975 cartons, resulting in nearly $15,000 in unpaid cigarette and sales taxes.

A federal law requires companies that ship cigarettes across state lines to release information about the sales to taxing authorities in the state where the purchaser lives.Pennsylvania has obtained records pertaining to about 27,000 buyers going back to the start of 2005. The state will attempt to contact all of them, according to an Associated Press report.

Pennsylvania assesses a $1.35-a-pack cigarette tax, and 6% sales tax. It is sending tax forms to the online and mail-order purchasers, and waiving penalties for those who pay or enroll in payment plans. At least 13 other states have also begun mining the sales data to collect their own taxes.