Thinking about prepaying some of your 2018 taxes in advance of limitations imposed by the Republican tax plan? Well, forget about it. The final version of the tax legislation includes a provision that would disallow a deduction in 2017 for any prepayment of 2018 state and local income taxes (otherwise known as SALT). Forbidding prepayment means taxpayers cannot take advantage of the current tax law, which is more generous. Currently, taxpayers who itemize can deduct those expenses — which can be burdensome in high-tax states — on their federal tax return. The GOP bill imposes a $10,000 deduction cap on the combined value of SALT and property taxes beginning in tax year 2018.

The tax-overhaul bill will likely be voted on this week in both the House and Senate. If both chambers pass the final version, the measure will head to President Donald Trump for his signature. While the $10,000 deduction cap for combined SALT and property taxes is one of the few tax breaks for individual taxpayers retained in the bill, it's important to remember it's only available to those who itemize. And for itemizing to make financial sense, the value of all your deductions need to exceed the standard deduction.

Chairman of the House Ways and Means Committee Rep. Kevin Brady, R-Texas, talks with President Donald Trump during a meeting on tax policy with Republican lawmakers in the Cabinet Room of the White House in Washington, DC on Thursday, Nov. 02, 2017. Jabin Botsford | The Washington Post | Getty Images