Personal information
Let’s start with the obvious items on any tax prep checklist.

Last year’s taxes, both your federal and — if applicable — state return. These aren’t strictly necessary, but they’re good refreshers of what you filed last year and the documents you used.

Social Security numbers for yourself, your spouse and all dependents. Remember, in addition to children, dependents can include elderly parents and others.

Income
Gather all the documents that confirm the money you received during the previous year.

- W-2 forms. Employers must issue your W-2 by Jan. 31, so keep an eye on your mailboxes, both physical and electronic.

- 1099 forms. Each of these ends with a different suffix, depending on the type of payment you received. For example, form 1099-MISC is for contract work. If you’re paid via a third party such as PayPal or Amazon, you’ll likely get a 1099-K. Investment earnings show up on 1099-INT for interest, 1099-DIV for dividends and 1099-B for broker-handled transactions.

Make sure you have documentation for each before you file:

- Retirement account contributions. You can deduct contributions to a traditional IRA or self-employed retirement account. Just be sure to stay within the contribution limits.

- Educational expenses. Students can claim a deduction for tuition and fees they paid, as well as for interest paid on a student loan. The IRS won’t accept your deduction claim without Form 1098-T, which shows your education transactions. Form 1098-E has details on your student loan.

- Medical bills. Medical costs could provide tax savings, but only if they total more than 7.5% of adjusted gross income for most taxpayers.

- Property taxes and mortgage interest. If your mortgage payment includes an amount escrowed for property taxes, that will be included on the Form 1098 your lender sends you. That document will also show how much home loan interest you can claim on Schedule A.

- Charitable donations. To ensure your generosity pays off at tax time, keep your receipts for charitable donations. The IRS could disallow your claim if you don’t have verification.

- Classroom expenses. If you’re a school teacher or other eligible educator, you can deduct up to $250 spent on classroom supplies.

- State and local taxes. You can deduct various other taxes, including either state and local income or sales taxes (up to $10,000, including property taxes). You don’t need receipts for the sales tax; the IRS provides tables with average amounts you can claim. The tax on a major purchase, however, can be added to the table amount, so keep those receipts.

Note that state income taxes paid should be on your W-2, but remember to add any state estimated taxes you paid during the year.