You can file a tax return without your 1099 forms, because (unless withholding has been taken, and appears on the form) you need not attach them to your return. However, since most taxpayers do not keep adequate records, and some income items are only reported by brokers on the 1099 form, you should generally wait until you receive your forms 1099. Keep in mind, that brokers frequently send multiple “corrected 1099′s” in the month’s that follow February, so (if you rely on the 1099′s) you may end up filing multiple amended returns. Depending on the type of securities you hold, it may be better to wait until closer to April to file.

Forms 1099 don’t completely track your stocks sold, interest or dividend income, or your income if you worked as an independent contractor. They provide someone else’s record of these items, which may or may not be accurate and probably will not be complete, unless this is your only broker, investment, client, etc.

Sometimes you need quite a bit of information to accurately do your tax returns. For instance, if you have an investment in the GLD, IAU, or SLV ETF’s, you will need to do several pages of calculations to determine the reportable amounts for 12 monthly “trust sales”, and the information to do so is not available until mid-February.

Although you may receive most 1099′s by the end of January, most brokers don’t send them out until the February 15th deadline. This is because they don’t receive the information from the various sources until early February, and don’t want (them or you) to have to file amended returns.

It is not usually necessary to file a 1040X mail to reconcile a discrepancy. An attachment to the original return, or a letter response to the IRS, is usually all that is needed. Of course, if there is a substantial adjustment to income that result in a change in your tax liability, and the 1099 is correct (which they often are not), then you would have to file a 1040X.

It is not always better to wait for the 1099s. If you keep proper records, you should be able to file as soon as you have received the requisite W-2 forms (which unfortunately MUST be attached, and thus place you at the mercy of the employer). If you are owed a substantial refund, and expect no surprises from the 1099′s you haven’t yet received, it makes more sense to file now, get your refund, and (if necessary) file a 1040X later in the year. The IRS doesn’t even begin cross-matching returns with 1099′s until well after April 15th, by which time your 1040X will have arrived.