all the following assumes the sale was of your stock in your corporation. if what was really sold was the assets of the company, maybe including assumption of liabilities, the reporting is completely different.
installment sale reporting - form 6252 - IRS pub 537
Contingent Payment Sale
A contingent payment sale is one in which the total selling price can’t be determined by the end of the tax year of sale. This happens, for example, if you sell your business and the selling price includes a percentage of its profits in future years.
If the selling price can’t be determined by the end of the tax year, you must use different rules to figure the contract price and the gross profit percentage than those you use for an installment sale with a fixed selling price.
For rules on using the installment method for a contingent payment sale, see Regulations section 15a.453-1(c).
this is complicated
(c)Contingent payment sales -
(1)In general. Unless the taxpayer otherwise elects in the manner prescribed in paragraph (d)(3) of this section, contingent payment sales are to be reported on the installment method. As used in this section, the term “contingent payment sale” means a sale or other disposition of property in which the aggregate selling price cannot be determined by the close of the taxable year in which such sale or other disposition occurs.
The term “contingent payment sale” does not include transactions with respect to which the installment obligation represents, under applicable principles of tax law, a retained interest in the property which is the subject of the transaction, an interest in a joint venture or a partnership, an equity interest in a corporation or similar transactions, regardless of the existence of a stated maximum selling price or a fixed payment term. See paragraph (c)(8) of this section, describing the extent to which the regulations under section 385 apply to the determination of whether an installment obligation represents an equity interest in a corporation.
This paragraph prescribes the rules to be applied in allocating the taxpayer's basis (including selling expenses except for selling expenses of dealers in real estate) to payments received and to be received in a contingent payment sale. The rules are designed appropriately to distinguish contingent payment sales for which a maximum selling price is determinable, sales for which a maximum selling price is not determinable but the time over which payments will be received is determinable, and sales for which neither a maximum selling price nor a definite payment term is determinable. In addition, rules are prescribed under which, in appropriate circumstances, the taxpayer will be permitted to recover basis under an income forecast computation.
(2)Stated maximum selling price -
(i)In general.
(A) contingent payment sale will be treated as having a stated maximum selling price if, under the terms of the agreement, the maximum amount of sale proceeds that may be received by the taxpayer can be determined as of the end of the taxable year in which the sale or other disposition occurs. The stated maximum selling price shall be determined by assuming that all of the contingencies contemplated by the agreement are met or otherwise resolved in a manner that will maximize the selling price and accelerate payments to the earliest date or dates permitted under the agreement. Except as provided in paragraph (c)(2)(ii) and (7) of this section (relating to certain payment recomputations), the taxpayer's basis shall be allocated to payments received and to be received under a stated maximum selling price agreement by treating the stated maximum selling price as the selling price for purposes of paragraph (b) of this section. The stated maximum selling price, as initially determined, shall thereafter be treated as the selling price unless and until that maximum amount is reduced, whether pursuant to the terms of the original agreement, by subsequent amendment, by application of the payment recharacterization rule (discribed in paragraph (c)(2)(ii) of this section), or by a subsequent supervening event such as bankruptcy of the obligor. When the maximum amount is subsequently reduced, the gross profit ratio will be recomputed with respect to payments received in or after the taxable year in which an event requiring reduction occurs. If, however, application of the foregoing rules in a particular case would substantially and inappropriately accelerate or defer recovery of the taxpayer's basis, a special rule will apply. See paragraph (c)(7) of this section.
(3)Fixed period -
(i)In general. When a stated maximum selling price cannot be determined as of the close of the taxable year in which the sale or other disposition occurs, but the maximum period over which payments may be received under the contingent sale price agreement is fixed, the taxpayer's basis (inclusive of selling expenses) shall be allocated to the taxable years in which payment may be received under the agreement in equal annual increments. In making the allocation it is not relevant whether the buyer is required to pay adequate stated interest. However, if the terms of the agreement incorporate an arithmetic component that is not identical for all taxable years, basis shall be allocated among the taxable years to accord with that component unless, taking into account all of the payment terms of the agreement, it is inappropriate to presume that payments under the contract are likely to accord with the variable component. If in any taxable year no payment is received or the amount of payment received (exclusive of interest) is less than the basis allocated to that taxable year, no loss shall be allowed unless the taxable year is the final payment year under the agreement or unless it is otherwise determined in accordance with the rules generally applicable to worthless debts that the future payment obligation under the agreement has become worthless. When no loss is allowed, the unrecovered portion of basis allocated to the taxable year shall be carried forward to the next succeeding taxable year. If application of the foregoing rules to a particular case would substantially and inappropriately defer or accelerate recovery of the taxpayer's basis, a special rule will apply. See paragraph (c)(7) of this section.
(4)Neither stated maximum selling price nor fixed period.
If the agreement neither specifies a maximum selling price nor limits payments to a fixed period, a question arises whether a sale realistically has occurred or whether, in economic effect, payments received under the agreement are in the nature of rent or royalty income. Arrangements of this sort will be closely scrutinized. If, taking into account all of the pertinent facts, including the nature of the property, the arrangement is determined to qualify as a sale, the taxpayer's basis (including selling expenses) shall be recovered in equal annual increments over a period of 15 years commencing with the date of sale. However, if in any taxable year no payment is received or the amount of payment received (exclusive of interest) is less than basis allocated to the year, no loss shall be allowed unless it is otherwise determined in accordance with the timing rules generally applicable to worthless debts that the future payment obligation under the agreement has become worthless; instead the excess basis shall be reallocated in level amounts over the balance of the 15 year term. Any basis not recovered at the end of the 15th year shall be carried forward to the next succeeding year, and to the extent unrecovered thereafter shall be carried forward from year to year until all basis has been recovered or the future payment obligation is determined to be worthless. The general rule requiring initial level allocation of basis over 15 years shall not apply if the taxpayer can establish to the satisfaction of the Internal Revenue Service that application of the general rule would substantially and inappropriately defer recovery of the taxpayer's basis. See paragraph (c)(7) of this section. If the Service determines that initially allocating basis in level amounts over the first 15 years will substantially and inappropriately accelerate recovery of the taxpayer's basis in early years of that 15-year term, the Service may require that basis be reallocated within the 15-year term but the Service will not require that basis initially be allocated over more than 15 years. See paragraph (c)(7) of this section.
(7)Special rule to avoid substantial distortion -
(i)In general. The normal basis recovery rules set forth in paragraph (c) (2) through (4) of this section may, with respect to a particular contingent payment sale, substantially and inappropriately defer or accelerate recovery of the taxpayer's basis.
(ii)Substantial and inappropriate deferral. The taxpayer may use an alternative method of basis recovery if the taxpayer is able to demonstrate prior to the due date of the return including extensions for the taxable year in which the first payment is received, that application of the normal basis recovery rule will substantially and inappropriately defer recovery of basis. To demonstrate that application of the normal basis recovery rule will substantially and inappropriately defer recovery of basis, the taxpayer must show (A) that the alternative method is a reasonable method of ratably recovering basis and, (B) that, under that method, it is reasonable to conclude that over time the taxpayer likely will recover basis at a rate twice as fast as the rate at which basis would have been recovered under the otherwise applicable normal basis recovery rule. The taxpayer must receive a ruling from the Internal Revenue Service before using an alternative method of basis recovery described in paragraph (c)(7)(ii) of this section.
(d)(3)Time and manner for making election -
(i)In general. An election under paragraph (d)(1) of this section must be made on or before the due date prescribed by law (including extensions) for filing the taxpayer's return for the taxable year in which the installment sale occurs. The election must be made in the manner prescribed by the appropriate forms for the taxpayer's return for the taxable year of the sale. A taxpayer who reports an amount realized equal to the selling price including the full face amount of any installment obligation on the tax return filed for the taxable year in which the installment sale occurs will be considered to have made an effective election under paragraph (d)(1) of this section. A cash method taxpayer receiving an obligation the fair market value of which is less than the face value must make the election in the manner prescribed by appropriate instructions for the return filed for the taxable year of the sale.
(ii)Election made after the due date. Elections after the time specified in paragraph (d)(3)(i) of this section will be permitted only in those rare circumstances when the Internal Revenue Service concludes that the taxpayer had good cause for failing to make a timely election. A recharacterization of a transaction as a sale in a taxable year subsequent to the taxable year in which the transaction occurred (e.g., a transaction initially reported as a lease later is determined to have been an installment sale) will not justify a late election. No conditional elections will be permitted. For a special transitional rule relating to certain taxable years for which a return is filed prior to February 19, 1981, see paragraph (d)(5) of this section.
