The return was filed from www.nto.com, a Web site owned by Nationtax Online, a business in Birmingham, Ala., that is the first company authorized by the I.R.S. to process such returns.

The challenge for retailers and vendors is to process returns at a proficiency level that allows quick, efficient and cost-effective collection and return of merchandise.

The IRS is granting this extension of time to file because the part of the e-file system that processes electronically filed returns of tax-exempt organizations will be off-line during January and February.

These centers do the actual tax processing; different types of returns are processed at the various centers (with some centers processing individual returns and others processing business returns).

In the last decade, the I.R.S. has been forced to process 13 percent more returns, with 15 percent fewer staff members.

The IRS must explain each new provision to taxpayers, write computer code so it can process returns affected by the provision, and train its auditors to identify improper claims.

It is a generalisation of the bistatic radar system, with one or more receivers processing returns from one or more geographically separated transmitters.

The new system of self-assessment has broad support, though some Labor Party leaders have called for a year's delay in adopting it, saying that the computers needed to process returns are not ready.

Now, as before, the problem is to balance two conflicting concerns - how to maintain security against unwarranted viewing, while also providing the necessary access to information that's needed to process returns properly.

Ernst & Young has used its outpost of 260 staff accountants in Bangalore to process several thousand "simple" individual and corporate returns a year over the last three years, he said.