technical analyst, who is knowledgeable about the preparation of interest computations on Federal tax liabilities and who has had extensive experience with the computerized records of the Internal Revenue Service, referred to as transcripts of account, which reflect account activity, such as assessments, payments, credits, and the like, for particular taxpayers. The Government's affidavit includes, as an exhibit, a document that was prepared on behalf of petitioner entitled "Listing of Differences-Sun's Interest Computations v. IRS' Interest Computations." This exhibit is referred to herein as petitioner's list of differences. It is petitioner's list of each of the errors that respondent allegedly made in computing interest.

There is also attached to the Government's affidavit petitioner's computation of the amount of interest that would have accrued with respect to petitioner's account for each of the years in issue if the differences described in petitioner's list were taken into account. Finally, there are attached to the Government's affidavit three schedules that were prepared on behalf of respondent to verify the accuracy of petitioner's computations. We note that, while we have been provided with petitioner's interest computations and respondent's verification of petitioner's computations, we have not been supplied with respondent's computations of interest.

On the basis of the information in the record, we have prepared three appendixes in which we have reproduced petitioner's computation of interest for each of the tax years in issue, 1979, 1981, and 1983. These appendixes are attached hereto as appendixes 1, 2, and 3, respectively.

Each appendix is in the nature of a transcript of petitioner's account with the Internal Revenue Service for one of the years in issue; i.e., 1979, 1981, or 1983. It shows all of the transactions that affect the balance of petitioner's account for the year. These transactions are shown in the appendix in the column designated "Other Events" (col. G). Some "events" increase petitioner's liability, such as income tax assessments, refunds, and the application of interim overpayments from the current year to the tax liability for other years. These are shown as positive numbers. Other "events" reduce petitioner's liability, such as tax payments, the carryback of a net operating loss from a later year, or the carryback of a

foreign tax credit from a later year. These are shown as negative numbers.

Each appendix shows the balance of petitioner's account as of various dates. The account balance on a particular date may be a positive number, indicating an interim underpayment, or a negative number, indicating an interim overpayment.

The account balance on a particular date comprises the prior transactions that were booked to the account, such as tax payments by petitioner, refunds to petitioner, and the like. The account balance also includes the interest computed on prior balances as noted in the columns designated overpayment interest (col. H) and underpayment interest (col. I).

Interest is computed on the balance of petitioner's account as follows. If the account balance is positive at the time interest is computed, i.e., indicating an interim underpayment, then the interest on that balance is so-called underpayment interest and is computed under section 6601(a) (see col. I). If the account balance is negative at the time interest is computed, i.e., indicating an interim overpayment, then the interest on that balance is so-called overpayment interest and is computed under section 6611(a) (see col. H). The number of days and the interest factors used in the interest computation are shown in each appendix. The amounts of underpayment interest and overpayment interest computed in these appendixes correlate with the amounts computed by petitioner and verified by respondent, except that there is a difference of less than $1 in 1981.

The parties agree that for each of the years in issue, the balance of petitioner's account with the Internal Revenue Service comprises the transactions recorded in the column entitled "Other Events" in the appropriate appendix. They also agree that the correct dollar amount of each of those transactions is the dollar amount shown in the appendix. Neither party has raised an issue about the method of computing interest, as reflected in petitioner's computation and respondent's verification, or the percentage interest factors used therein.

The parties disagree about the dates on which many of the transactions should be recorded in petitioner's account. The substantive issues raised by petitioner's amendment to petition and list of differences all involve the date on which each

of certain of the agreed transactions is recorded in petitioner's account for purposes of computing interest. In general, petitioner contends that the items noted in its list of differences are transactions that were recorded in petitioner's account on dates that caused either too much underpayment interest under section 6601 to be charged or too little overpayment interest under section 6611 to be allowed on the account.

For example, with respect to 1979, petitioner contends that the amount of underpayment interest respondent charged in 1979, $1,948,026, is $594,943 too high when compared to petitioner's computation of the amount of underpayment interest, $1,353,083, shown in appendix 1. Similarly, petitioner contends that the amount of overpayment interest respondent allowed for 1979, $4,304,396, is $2,042,274 too low when compared to petitioner's computation of the amount of overpayment interest, $6,346,670, shown in appendix 1. The following schedule compares the overpayment interest and underpayment interest computed by both parties for each of the years in issue:

In considering the issues raised by respondent's motion, it is important to note that the interest computed at any particular time is based upon the outstanding balance in petitioner's account. An interest factor is applied to that balance for the number of days that elapsed before the date of the next event that changed the account balance, or before the date of a change in the rate of interest. If the effective date of a transaction were changed, then that would not only cause the account balance to change; it would also cause the amount of interest, and possibly the kind of interest (i.e.,

underpayment or overpayment interest), computed on that balance to change. Furthermore, the aggregate amounts of underpayment and overpayment interest computed for the year would also change.

For example, if petitioner's computation for 1979 were changed to reflect respondent's position with respect to one of the issues raised by petitioner for that year, the effective date of the carryback of a foreign tax credit of $3,876,645 from 1981, then the resulting recomputation of the account is shown in appendix 4. As shown in appendix 4, making that one change causes the aggregate amount of underpayment interest to be increased to $2,021,767 (see appendix 4) from $1,353,083 (see appendix 1), and it causes the aggregate amount of overpayment interest to be reduced to $5,272,357 (see appendix 4) from $6,346,670 (see appendix 1). This illustrates the fact that the computations are interrelated, and underpayment interest and overpayment interest cannot be computed separately.

Discussion

This Court exercises only such jurisdiction as is conferred on it by statute. See sec. 7442. By statute, we are authorized to redetermine the amount of a deficiency for a particular taxable period as to which the Commissioner issued a notice of deficiency and the taxpayer petitioned the Court for review. See secs. 6212, 6213, and 6214; Monge v. Commissioner, 93 T.C. 22, 27 (1989). As to any such taxable period for which a petition was filed in this Court, if we find there is no deficiency, then we are authorized to determine the amount of an overpayment. See sec. 6512. Our jurisdiction to determine an overpayment is set forth in section 6512(b)(1) and (3), which provides in pertinent part:

SEC. 6512(b). OVERPAYMENT DETERMINED BY TAX COURT.

(1) JURISDICTION TO DETERMINE.-Except as provided by paragraph (3) * if the Tax Court finds that there is no deficiency and further finds that the taxpayer has made an overpayment of income tax for the same taxable year, *** in respect of which the Secretary determined the deficiency, or finds that there is a deficiency but that the taxpayer has made an overpayment of such tax, the Tax Court shall have jurisdiction to determine the amount of such overpayment ***

* *

(3) LIMIT ON AMOUNT OF CREDIT OR REFUND. -No such credit or refund shall be allowed or made of any portion of the tax unless the Tax Court determines as part of its decision that such portion was paid * * *

During the pendency of a case in this Court, our jurisdiction is exclusive, and, with a few exceptions, another proceeding may not be commenced or, if already commenced, is stayed. See secs. 6213(a), 6512(a), 7422(e); Hallmark Cards, Inc. v. Commissioner, 111 T.C. 266, 271 (1998). The filing of a timely petition in this Court in response to a notice of deficiency gives the Court exclusive jurisdiction and precludes the taxpayer from later bringing a refund suit for the same type of tax for the same taxable period. Sec. 6512(a); see Estate of Ming v. Commissioner, 62 T.C. 519, 521 (1974); Dorl v. Commissioner, 57 T.C. 720 (1972), affd. 507 F.2d 406 (2d Cir. 1974).

Respondent issued a notice of deficiency to petitioner for the years in issue, and petitioner invoked our deficiency jurisdiction by filing a timely petition. In the pleadings, petitioner asserts that there is no deficiency in any of the years in issue, and it claims an overpayment for each of those years. As mentioned above, petitioner's overpayment claims include overpayments consisting in part of interest respondent computed on the interim underpayment balances reflected in petitioner's account, so-called underpayment interest. Petitioner contends that the amounts of underpayment interest respondent computed are too high. Petitioner's overpayment claims also include overpayments consisting in part of interest computed on the interim overpayment balances reflected in petitioner's account, so-called overpayment interest. Petitioner contends that the amounts of overpayment interest respondent computed are too low.

Respondent concedes that this Court has jurisdiction under section 6512(b) to determine an overpayment based upon petitioner's claim that it overpaid underpayment interest. Respondent acknowledges that excess underpayment interest which has been assessed and paid by petitioner "becomes part of the overpayment, i.e., a payment in excess of that which is properly due." This concession is based upon Estate of Baumgardner v. Commissioner, 85 T.C. 445 (1985). Respondent asserts that "the Court, however, does not have jurisdiction to adjudicate petitioner's claimed overpayments