If you’re expecting a refund this season, it’s critical to file a complete and accurate tax return to avoid “extensive processing” and delays, according to the IRS. One of the keys to error-free filing is including all your required tax forms, known as information returns, which employers and financial institutions send yearly, with copies going to the IRS and taxpayer. If you skip tax forms received by the agency, the IRS systems may flag your return and mail you a notice, explained Sheneya Wilson, a certified public accountant and founder of Fola Financial in New York. More from Personal Finance: Tax season opens for individual filers Jan. 23, says IRS Nearly one-third of Americans will rely on tax refunds, survey finds What to know about the 1099-K tax reporting change for Venmo, PayPal”Missing tax documents are definitely going to cause a refund delay,” Wilson said. Whether you’re working with a tax professional or filing on your own, here’s what to know about your tax forms — and when to expect them. When to expect your tax forms While most tax forms have a Jan. 31 deadline, others aren’t Due until mid-February or beyond, said certified financial planner John Loyd, owner at The Wealth Planner in Fort Worth, Texas. For example, the deadline for 1099-B for capital gains and losses and 1099-DIV for dividends and distributions is Feb. 15. But some investment firms get an extension from the IRS for more time to validate forms and avoid corrections, meaning you may not receive these forms until March, Loyd said. If you do need a corrected form, it can slow down your filing process because it takes time for the investment firm to update and reissue your documents, he said. Regardless of your situation, it’s important to have all the necessary forms handy before filing your return, Loyd said. “It’s 1,000 times better” to file correctly the first time, he added, noting that IRS notices may take months to resolve. Review last year’s return ‘page-by-page’ If you’re not sure which tax forms to expect, experts say last year’s tax return is a great starting point.” I go page-by-page with the prior year and current year’s [returns],” said Marianela Collado, a CFP and CEO of Tobias Financial Advisors in Plantation, Florida. She is also a CPA. “That’s always a good check,” she said. For earnings, some of the common forms include a W-2 for wages, 1099-NEC for contract or gig economy work, 1099-G for unemployment income and 1099-R for retirement plan distributions.By 2022, you probably won’t receive a 1099-K for payment apps such as Vemno or PayPal unless there were more than 200 payments worth an aggregate above $20,000.If you receive this form by mistake, the IRS said, it is working on guidance.Of course, it’s also important to make sure the numbers on your tax return match those on your 1099s because “That’s something that could trigger a delay,” Collado said. As for tax breaks, you may need forms 1098 for mortgage interest, 5498 for individual retirement account deposits, 5498-SA for health savings account contributions, 1098-T for tuition, 1098 -E for student loan interest and more.