Philadelphia, April 15, 2013– Owing to technical difficulties on City of Philadelphia’s Revenue Department website on Sunday, the City has extended the deadline to file returns for the Business Income and Receipts Tax, the Net Profits Tax, the School Income Tax and the Earnings Tax.rnrn rnrnThe new deadline is midnight Tuesday, April 16. Tax filers have until then to file electronically or to mail their return with a Tuesday postmark.