So before things get too hectic with the holidays, here's the list of considerations that should be dealt with, at least in part, before the Old Year passes.

5. Qualified Small Employer Health Reimbursement Accounts

Qualified Small Employer Health Reimbursement Arrangements (QSEHRAs) were established in December 2016 through the 21^st Century Cures Act.

For non-ALE (applicable large employer) small employers that do not provide group health coverage, these arrangements give them a way of reimbursing employees for the cost of individual insurance, and/or qualified medical expenses, on a pretax basis.

The programs require the benefit be provided to all eligible employees, have a notice requirement and allow only employer contributions to a statutory maximum amount.

4. Credit for Small Employer Pension Plan Startup Costs

The Credit for Small Employer Pension Plan Startup Costs, which provides a tax credit to eligible employers who start a 401(k) plan, is once more available to employers with no more than 100 employees who received at least $5,000 in compensation for the tax year.

The credit, which is up to $500 per year for the first credit year and each of the following two tax years, is allowed to offset the costs of establishing an eligible plan as well as educating employees about the plan.

3. Accelerated W-2 form filing

Tax year 2017 is the second year of federal W-2 filing accelerated due dates, with the deadline January 31, 2018.

The Social Security Administration has indicated that the number of late W-2s filed in 2017 almost doubled compared to 2016, and the number of corrections filed on Form W-2C increased more than 30 percent from last year.

Employers need to ensure all W-2s are submitted on time to avoid late or nonfiling penalties assessed by the IRS.

For tax year 2017 filing, seven additional states (AZ, AR, KS, ME, MO, MT, and NE) are following the federal example, accelerating their W-2 filing deadline to January 31 and bringing the total number of states requiring accelerated W-2 filing to 35.

2. Affordable Care Act filing

For tax year 2017, businesses that are defined as an applicable large employer (ALE), under the Employer Shared Responsibility (ESR) provision of the ACA have to provide a detailed reporting of health care coverage.

Don't be misled by the term applicable large employer — it deserves researching.

For the previous two years there was transition relief, but for 2017 that's no longer the case for either how employers file or how they offer coverage.

So to avoid the risk of substantial penalties, employers need to do due diligence and ensure that information reported on Forms 1094-C/1095-C is timely and accurate.

In addition, both recent Internal Revenue Service communication on health care coverage reporting for the individual mandate and recent updates on the IRS ESR question and answer site indicate that the IRS is now focusing on enforcement of and collection on the assessment for the ACA shared responsibility provisions.

The IRS has provided more specifics on how employers will know that they may owe a shared responsibility payment, as well as instructions on how they should respond to payment notices.

The agency has also indicated that in late 2017, employers will begin to receive notices of a potential assessment for 2015. So some employers will need to research these notices, correct any errors in previous filings and communicate with the IRS, at the same time they're preparing for current-year obligations.

1. GOP-proposed tax plans

Even though they have to make decisions now on tax filing, employers will have to keep in mind that changes in the federal tax code are likely on the way.

As of this publication date, the Senate Budget Committee voted to send the Republican Senate tax bill to the floor committee. 

Related: 7 key changes to retirement plans under the House and Senate tax bills

Even though tax legislation has been introduced in the House and in the Senate, there are differences between the two plans that will have to be reconciled before passage. And therein lies room for change—assuming that legislators can even agree on reconciliation.

But that doesn't let business owners off the hook; they'll still have to make reasonable assessments of what they anticipate, based on the best information available on tax reform and the potential impacts on their business.

Right now, Republicans are pushing for rate reductions, especially for businesses. If businesses are able to accelerate deductions, they can take advantage of current rates, which would be higher than subsequent years if tax reform legislation passes.

In addition, some business deductions are set to be eliminated as the legislation is currently structured.

Also, deferral of business income, where feasible under accounting methods, would result in that income being taxed at a future rate, which could be lower if tax reform legislation is enacted.