COUPNUM
Quirk foundCategory: Financial · Last tested 2026-09-01
Real compatibility results for the COUPNUM function: executed in Excel for the web, Google Sheets and LibreOffice Calc, with desktop Excel behavior from Microsoft’s official documentation (we do not run desktop Excel — Excel for the web is a different application and is executed separately). Syntax and links to that documentation are below.
Support matrix
| Engine | Documented | Live-tested | Verdict |
|---|---|---|---|
| Excel (desktop) | Yes | No — documented only | n/a |
| Excel for the web | — | Yes (recalc, 2026-09-01) | Supported, behaves as documented |
| Google Sheets | Yes | Yes (Drive import, 2026-08-31) | Supported, behaves as documented |
| LibreOffice Calc | Yes | Yes (25.8.7.3, 2026-08-31) | Quirk found |
LibreOffice version history
We executed the same test cases under each LibreOffice release to show exactly when COUPNUM’s support changed — not documentation claims, real results.
| LibreOffice version | Verdict | Tested |
|---|---|---|
| 24.2.0.3 | Quirk found | 2026-08-31 |
| 24.8.7.2 | Quirk found | 2026-08-31 |
| 25.2.0.3 | Quirk found | 2026-08-31 |
| 25.8.7.3 | Quirk found | 2026-08-31 |
Why isn't COUPNUM working in LibreOffice?
COUPNUM exists in LibreOffice 25.8.7.3, but it is not a drop-in match for
Excel — our executed tests found real behavioral differences (detailed in the test results on this
page). If a formula that works in Excel or Google Sheets misbehaves in LibreOffice, compare your usage
against the failing cases above before assuming your data is wrong.
Discovered quirks
-
=COUPNUM(A2,A3,3,A5) on
LibreOffice Calc returned
#VALUE!, but the documented/expected
result is #NUM!.
Provenance
Excel documents: "If frequency is any number other than 1, 2, or 4, COUPNUM returns the #NUM! error value."; MISMATCH vs expected: expected '#NUM!', got '#VALUE!'
-
=COUPNUM(A2,A3,A4,5) on
LibreOffice Calc returned
#VALUE!, but the documented/expected
result is #NUM!.
Provenance
Excel documents: "If basis < 0 or if basis > 4, COUPNUM returns the #NUM! error value."; MISMATCH vs expected: expected '#NUM!', got '#VALUE!'
-
=COUPNUM(A3,A2,A4,A5) on
LibreOffice Calc returned
#VALUE!, but the documented/expected
result is #NUM!.
Provenance
Excel documents: "If settlement >= maturity, COUPNUM returns the #NUM! error value."; MISMATCH vs expected: expected '#NUM!', got '#VALUE!'
Executed test cases
Excel for the web (executed 2026-09-01 via OneDrive recalculation)
These values come from Excel for the web, not from desktop Excel. They are two different implementations of the calculation engine, and this run measured only the web one: the corpus was uploaded to OneDrive as .xlsx, recalculated by Excel for the web on open, and downloaded again for readback. Excel for the web is a rolling service with no pinnable version, so the run is identified by its date. Where a value here disagrees with the Expected column — which is Microsoft’s documentation of the desktop product — we cannot tell you whether the web engine diverges from the desktop one or the documentation is wrong about both, because we do not run desktop Excel.
| Formula | Description | Result | Expected | Verdict |
|---|---|---|---|---|
| =COUPNUM(A2,A3,A4,A5) | Microsoft's documented worked example: number of coupons payable between settlement and maturity, semiannual | 4 | 4ProvenanceMicrosoft's page publishes this example's result as 4. Setup serials are the dates the page prints: 39107 = 2007-01-25 (settlement) and 39767 = 2008-11-15 (maturity). Counting coupon dates back from maturity in six-month steps gives 2008-11-15, 2008-05-15, 2007-11-15, 2007-05-15, 2006-11-15; exactly four of them fall after the 2007-01-25 settlement, which is the documented 4 |
Matched |
| =COUPNUM(A2,A3,1,A5) | The same bond paying annually instead of semiannually | 2 | 2ProvenanceWith frequency 1 the coupon dates are 2008-11-15 and 2007-11-15 (and 2006-11-15 before settlement), so exactly 2 coupons fall after the 2007-01-25 settlement -- half the semiannual count, as it must be for the same term. This discriminates the frequency argument |
Matched |
| =COUPNUM(A2,A3,3,A5) | A frequency of 3, which is not one of the permitted values | #NUM! | #NUM!ProvenanceExcel documents: "If frequency is any number other than 1, 2, or 4, COUPNUM returns the #NUM! error value." |
Matched |
| =COUPNUM(A2,A3,A4,5) | A day-count basis of 5, above the documented maximum of 4 | #NUM! | #NUM!ProvenanceExcel documents: "If basis < 0 or if basis > 4, COUPNUM returns the #NUM! error value." |
Matched |
| =COUPNUM(A3,A2,A4,A5) | Settlement and maturity swapped, so settlement is after maturity | #NUM! | #NUM!ProvenanceExcel documents: "If settlement >= maturity, COUPNUM returns the #NUM! error value." |
Matched |
Google Sheets (executed 2026-08-31 via Drive import)
Google Sheets is a rolling service with no pinnable version, so this run is identified by its date. The corpus was imported to Drive as .xlsx, recalculated by Sheets, and exported back for readback.
| Formula | Description | Result | Expected | Verdict |
|---|---|---|---|---|
| =COUPNUM(A2,A3,A4,A5) | Microsoft's documented worked example: number of coupons payable between settlement and maturity, semiannual | 4 | 4ProvenanceMicrosoft's page publishes this example's result as 4. Setup serials are the dates the page prints: 39107 = 2007-01-25 (settlement) and 39767 = 2008-11-15 (maturity). Counting coupon dates back from maturity in six-month steps gives 2008-11-15, 2008-05-15, 2007-11-15, 2007-05-15, 2006-11-15; exactly four of them fall after the 2007-01-25 settlement, which is the documented 4 |
Matched |
| =COUPNUM(A2,A3,1,A5) | The same bond paying annually instead of semiannually | 2 | 2ProvenanceWith frequency 1 the coupon dates are 2008-11-15 and 2007-11-15 (and 2006-11-15 before settlement), so exactly 2 coupons fall after the 2007-01-25 settlement -- half the semiannual count, as it must be for the same term. This discriminates the frequency argument |
Matched |
| =COUPNUM(A2,A3,3,A5) | A frequency of 3, which is not one of the permitted values | #NUM! | #NUM!ProvenanceExcel documents: "If frequency is any number other than 1, 2, or 4, COUPNUM returns the #NUM! error value." |
Matched |
| =COUPNUM(A2,A3,A4,5) | A day-count basis of 5, above the documented maximum of 4 | #NUM! | #NUM!ProvenanceExcel documents: "If basis < 0 or if basis > 4, COUPNUM returns the #NUM! error value." |
Matched |
| =COUPNUM(A3,A2,A4,A5) | Settlement and maturity swapped, so settlement is after maturity | #NUM! | #NUM!ProvenanceExcel documents: "If settlement >= maturity, COUPNUM returns the #NUM! error value." |
Matched |
LibreOffice Calc 25.8.7.3 (tested 2026-08-31)
| Formula | Description | Result | Expected | Verdict |
|---|---|---|---|---|
| =COUPNUM(A2,A3,A4,A5) | Microsoft's documented worked example: number of coupons payable between settlement and maturity, semiannual | 4 | 4ProvenanceMicrosoft's page publishes this example's result as 4. Setup serials are the dates the page prints: 39107 = 2007-01-25 (settlement) and 39767 = 2008-11-15 (maturity). Counting coupon dates back from maturity in six-month steps gives 2008-11-15, 2008-05-15, 2007-11-15, 2007-05-15, 2006-11-15; exactly four of them fall after the 2007-01-25 settlement, which is the documented 4 |
Matched |
| =COUPNUM(A2,A3,1,A5) | The same bond paying annually instead of semiannually | 2 | 2ProvenanceWith frequency 1 the coupon dates are 2008-11-15 and 2007-11-15 (and 2006-11-15 before settlement), so exactly 2 coupons fall after the 2007-01-25 settlement -- half the semiannual count, as it must be for the same term. This discriminates the frequency argument |
Matched |
| =COUPNUM(A2,A3,3,A5) | A frequency of 3, which is not one of the permitted values | #VALUE! | #NUM!ProvenanceExcel documents: "If frequency is any number other than 1, 2, or 4, COUPNUM returns the #NUM! error value." |
Mismatch |
| =COUPNUM(A2,A3,A4,5) | A day-count basis of 5, above the documented maximum of 4 | #VALUE! | #NUM!ProvenanceExcel documents: "If basis < 0 or if basis > 4, COUPNUM returns the #NUM! error value." |
Mismatch |
| =COUPNUM(A3,A2,A4,A5) | Settlement and maturity swapped, so settlement is after maturity | #VALUE! | #NUM!ProvenanceExcel documents: "If settlement >= maturity, COUPNUM returns the #NUM! error value." |
Mismatch |
Docs & syntax
- Excel (desktop): official documentation
- Google Sheets: official documentation
- LibreOffice Calc: official documentation
Where COUPNUM behaves differently
- Bond and treasury functions after a migration: what actually breaks
Executed across 26 fixed-income functions and 161 cases: ODDFPRICE and ODDFYIELD are literal stubs in LibreOffice, TBILLPRICE prices a two-year bill, INTRATE's default basis loses a day, and MDURATION is wrong on actual/actual. 83 of 84 documented #NUM! cases arrive as #VALUE!. Google Sheets matched 127 of 161.