CUMPRINC_ADD Function (OpenOffice Calc)

• Introduced: First release not established; documented by OpenOffice.org 3.3.
• Supported in: Apache OpenOffice 4.1.16; no final supported release is established.
• Scope: English desktop Calc, Analysis add-in compatibility identity and semicolon-separated formulas.
• Checked: October 14, 2026. One ordinary English-name formula was directly entered and recalculated in 4.1.16 on Linux x86-64, Build 9816. The table contains independent references; the failed generated-ODF import is separate.

CUMPRINC_ADD is the Analysis add-in’s cumulative-principal function. It returns the signed principal repaid over the requested payment interval, excluding interest. It is separately registered from core CUMPRINC even when ordinary inputs produce the same amounts. Release implementation.

=CUMPRINC_ADD(Rate;Nper;PV;StartPeriod;EndPeriod;Type)

• Rate: positive interest rate per payment period.
• Nper: positive total number of periods; use an integer.
• PV: positive initial loan value.
• StartPeriod, EndPeriod: inclusive integer payment numbers from 1 through Nper.
• Type: 0 for end-of-period payments or 1 for beginning-of-period payments. This add-in explicitly rejects other integer Type values.

All six arguments are required. Nper, the two interval limits and Type are declared as signed 32-bit integer parameters in the add-in interface. The examples use exact ordinary integers.

These values follow the stated mathematical formulas and the inspected integer-input contract. They are not presented as eight native executions. Results are rounded to twelve decimal places where needed.

For the twelve-payment loan in the first example, periods 1 through 3 repay approximately 238.919714574243 of principal. The function returns −238.919714574243, so the remaining positive balance is 1000+CUMPRINC_ADD(.01;12;1000;1;3;0), approximately 761.080285425757.

The full twelve-payment principal total is −1000. That is not the total payment outflow: interest adds approximately −66.185464140100. Keep principal reduction separate from borrowing cost in a schedule or summary.

The first end-of-period payment is approximately −88.848788678342. With interest −10, its principal component is −78.848788678342. This direct balance recurrence independently checks the cumulative add-in calculation.

For the 24-payment loan at 0.5% per period, the first twelve principal portions sum to approximately −485.041840313371; the second twelve sum to −514.958159686629. They add to −1000. With beginning timing, the first payment has no interest, so its full approximately −87.969097701328 amount reduces principal.

The release rejects a nonpositive rate, principal or total count, invalid interval bounds and integer Type values other than 0 or 1. The reference cases use valid intervals only. Rates and payment counts must use the same period unit; a monthly rate paired with a number of years creates a different loan.

The add-in’s period arguments are integer parameters. These tests do not establish how every fractional, empty or text argument is converted into that interface. In particular, do not transplant the core function’s flooring description without checking the add-in conversion path.

The directly entered English formula =CUMPRINC_ADD(0.01;12;1000;1;12;0) produced the saved result -1000. The English entry and its serialized identity were reviewed together; an ODF canonical spelling alone cannot distinguish every core function from its compatibility add-in.

An earlier generated ODF used fully qualified Analysis service names. All eight import-path attempts for this function displayed #NAME?, despite passing recalculation controls. Those errors do not establish that the English function is unsupported. They also do not count as successful reference-case executions. Do not copy a fully qualified storage name into a normal formula expecting it to behave like the English name.

CUMPRINC, PPMT, PMT.

• Function-specific release implementation
• Separate English and ODF add-in identities
• GetRmz calculation helper
• GetZw calculation helper

Only the single direct-entry case above is successful native function evidence in this guide. The remaining table values and explanatory identities are independently calculated. The failed generated-ODF workbook, including its informational attribute-load warning, is retained separately. No original XLSX execution, other locale, platform or release is implied.