If you dont have all your documents, your tax accountant will be able to help you track down the missing information.
If You Are Missing a W-2 Form
You can ask your employer to send new a copy of your W-2. Some employers charge a nominal fee for this service. Employers are required by law to keep copies of your W-2s and other payroll information for at least four years.
If You Are Missing a 1099 Form
Form 1099 reports interest, dividends, brokerage trades, and self-employment income.
Banks may have tax documents available for downloading from their web site, or you can call their customer service number to get a new 1099 mailed to you.
Your broker will be able to mail you a copy of your 1099 to report stock trading and other investment activity. Or you might be able to download a copy from the brokerage web site.
If you earned more than $600 as a consultant or independent contractor, your client is required to send you a 1099-MISC to report your income. Even if you didn't receive a 1099, you are still required to report the income to the IRS. Give your accountant copies of your invoices.
If All Else Fails, Ask the IRS for Copies of Your Tax Documents
Remember, the IRS receives copies of all these forms. It is your right to request copies of your tax documents from the IRS.
Your 2007 tax documents will not be fully loaded into the IRS system until sometime in August 2008. If you really need some information to finish your tax return, be sure to file an extension before April 15.
Your tax accountant is able to request these documents from the IRS for you, or you can do it yourself. Do it yourself by calling the IRS at 1-800-829-1040 and ask the representative for your "wage and income transcript". This is the IRS phrase for your tax documents. If you need copies of your W2s and other documents for an earlier year, the IRS keeps your documents in their database for four years. So you need to file your back taxes can get copies of your W2s and other tax documents going back four years.
If you want your accountant to get these documents, you will need to sign IRS Form 8821 Tax Information Authorization (PDF, 4 pages). The IRS will mail or fax the information they have.