There are various strategies that can be used by someone with a job to avoid paying estimated taxes with respect to income not subject to withholding. Some strategies include:
However, be sure that the strategies you use address not only the income tax on your contract work but also any self-employment tax that may be owed.
Items directly reducing income. Personal deductions such as for mortgage interest, state and local taxes, and charitable contributions are allowed only if deductions are itemized on Schedule A, but deductions such as for alimony, capital losses, moving expenses to a new job location, business losses, student loan interest, and IRA and Keogh deductions are deducted from gross income even if itemized deductions are not claimed.