You can't prepare your tax return accurately unless you have all the tax documents you expect to get. However, the IRS has different deadlines for the employers, financial institutions, and others who are responsible for reporting tax information to get your tax documents to you. Here's a short list of common forms and when you should expect to get them -- or when they already should have been in your hands.
W-2s: Jan. 31
Form W-2s have any income you get from your employer for wages or salaries, and your employer should have gotten that form to you by Jan. 31. Technically, the requirement is for the W-2 to be sent out, so there's a small chance that mail delays would make you wait until early February to receive it. Nevertheless, you should contact your employer now if you still haven't gotten a W-2 for a job that you worked in 2016. If you still file a paper return rather than filing electronically, you'll actually need that physical form, because it's one of the few forms that the IRS makes you enclose along with the tax return. Moreover, because W-2s include information on how much tax you had withheld from your check, it's critical to calculate your tax refund.
Most 1099s: Jan. 31
1099 forms have a wide variety of information, ranging from investment-related items like 1099-INT for interest, 1099-DIV for dividends, and 1099-R for distributions from retirement plans to 1099-G for unemployment benefits and prior-year tax refunds and 1099-MISC for nonemployee compensation. Most of these forms must be sent to recipients by Jan. 31.
Some 1099s: Feb. 15
Institutions get a break on filing some of the more complex 1099 forms, with a deadline that extends to Feb. 15. Those include Form 1099-B, which reports proceeds from sales of investments held at brokerage companies, and Form 1099-S, which reports the gross proceeds from the sale of real estate. A couple of 1099 forms have later due dates. In addition, if your Form 1099-MISC for nonemployee compensation includes proceeds paid to attorneys or substitute dividend or tax-exempt interest payments, then the reporting party has until Feb. 15 to get your 1099-MISC to you.
1098 Forms: Jan. 31
Form 1098 is the tax form that mortgage lenders use to report the deductible interest that you paid on your mortgage throughout the year. There are other similar forms that report deductible items, such as Form 1098-E for student loan interest payments and 1098-T for tuition paid for higher education. These forms are required to be sent to borrowers by Jan. 31. Again, without these forms, you won't necessarily know how much your deductions will be, especially if your mortgage lender also collected payments that go toward paying tax-deductible real estate taxes.
Schedule K-1: March 15 or April 15
If you own interested in various business entities that are structured as partnerships for tax purposes, then you can expect to receive a Schedule K-1 that includes your share of the partnership's income. The most common K-1s that ordinary investors receive is for master limited partnerships, which are typically structured to require reporting in this manner. The relevant IRS publications say that K-1s are due from most partnership by April 15 and by March 15 if a large partnership makes a relevant election for treatment as such. However, many K-1 providers are late in gathering the information they need to prepare the form. If you expect K-1s, be sure to track them closely and avoid filing until you're sure that you have every one you expect. That way, you won't have to file an amended return.
How to get what you need
Contract your financial institution or other information provider if your forms don't get to you on time. Even if you can prepare your taxes without, it's important to be sure that the IRS has the same information that you do. Otherwise, your return could trigger red flags that could get you audited -- even if it's entirely someone else's fault.
No one wants to wait for tax documents. By knowing when you should have them, you can be smarter about when to file and when to push to get the information you need.