diff --git a/icu4c/source/i18n/number_capi.cpp b/icu4c/source/i18n/number_capi.cpp
index 9c150931bf..16d87bb188 100644
--- a/icu4c/source/i18n/number_capi.cpp
+++ b/icu4c/source/i18n/number_capi.cpp
@@ -9,8 +9,8 @@
 // Helpful in toString methods and elsewhere.
 #define UNISTR_FROM_STRING_EXPLICIT
 
-#include "numparse_types.h"
 #include "number_utypes.h"
+#include "numparse_types.h"
 #include "unicode/numberformatter.h"
 #include "unicode/unumberformatter.h"
 
@@ -159,14 +159,14 @@ unumf_resultToString(const UFormattedNumber* uresult, UChar* buffer, int32_t buf
 
 U_CAPI UBool U_EXPORT2
 unumf_resultNextFieldPosition(const UFormattedNumber* uresult, UFieldPosition* ufpos, UErrorCode* ec) {
+    const UFormattedNumberData* result = UFormattedNumberData::validate(uresult, *ec);
+    if (U_FAILURE(*ec)) { return FALSE; }
+
     if (ufpos == nullptr) {
         *ec = U_ILLEGAL_ARGUMENT_ERROR;
         return FALSE;
     }
 
-    const UFormattedNumberData* result = UFormattedNumberData::validate(uresult, *ec);
-    if (U_FAILURE(*ec)) { return FALSE; }
-
     FieldPosition fp;
     fp.setField(ufpos->field);
     fp.setBeginIndex(ufpos->beginIndex);
@@ -181,14 +181,14 @@ unumf_resultNextFieldPosition(const UFormattedNumber* uresult, UFieldPosition* u
 U_CAPI void U_EXPORT2
 unumf_resultGetAllFieldPositions(const UFormattedNumber* uresult, UFieldPositionIterator* ufpositer,
                                  UErrorCode* ec) {
+    const UFormattedNumberData* result = UFormattedNumberData::validate(uresult, *ec);
+    if (U_FAILURE(*ec)) { return; }
+
     if (ufpositer == nullptr) {
         *ec = U_ILLEGAL_ARGUMENT_ERROR;
         return;
     }
 
-    const UFormattedNumberData* result = UFormattedNumberData::validate(uresult, *ec);
-    if (U_FAILURE(*ec)) { return; }
-
     auto* helper = reinterpret_cast<FieldPositionIterator*>(ufpositer);
     result->string.getAllFieldPositions(*helper, *ec);
 }
@@ -197,7 +197,6 @@ U_CAPI void U_EXPORT2
 unumf_closeResult(UFormattedNumber* uresult) {
     UErrorCode localStatus = U_ZERO_ERROR;
     const UFormattedNumberData* impl = UFormattedNumberData::validate(uresult, localStatus);
-    if (U_FAILURE(localStatus)) { return; }
     delete impl;
 }
 
@@ -205,7 +204,6 @@ U_CAPI void U_EXPORT2
 unumf_close(UNumberFormatter* f) {
     UErrorCode localStatus = U_ZERO_ERROR;
     const UNumberFormatterData* impl = UNumberFormatterData::validate(f, localStatus);
-    if (U_FAILURE(localStatus)) { return; }
     delete impl;
 }
 
diff --git a/icu4c/source/i18n/plurrule_impl.h b/icu4c/source/i18n/plurrule_impl.h
index 43ca84f27f..3ab445d584 100644
--- a/icu4c/source/i18n/plurrule_impl.h
+++ b/icu4c/source/i18n/plurrule_impl.h
@@ -106,7 +106,7 @@ static const UChar LOW_W = ((UChar) 0x0077);
 static const UChar LOW_Y = ((UChar) 0x0079);
 static const UChar LOW_Z = ((UChar) 0x007A);
 
-};
+}
 
 
 static const int32_t PLURAL_RANGE_HIGH = 0x7fffffff;
diff --git a/icu4c/source/i18n/unicode/numberformatter.h b/icu4c/source/i18n/unicode/numberformatter.h
index 47b4f9a7ae..5ec1018223 100644
--- a/icu4c/source/i18n/unicode/numberformatter.h
+++ b/icu4c/source/i18n/unicode/numberformatter.h
@@ -13,11 +13,11 @@
 #include "unicode/fieldpos.h"
 #include "unicode/fpositer.h"
 #include "unicode/measunit.h"
-#include "unicode/unumberformatter.h"
 #include "unicode/nounit.h"
 #include "unicode/plurrule.h"
 #include "unicode/ucurr.h"
 #include "unicode/unum.h"
+#include "unicode/unumberformatter.h"
 #include "unicode/uobject.h"
 
 #ifndef U_HIDE_DRAFT_API
diff --git a/icu4c/source/test/cintltst/unumberformattertst.c b/icu4c/source/test/cintltst/unumberformattertst.c
index dc3946f396..0b35c46332 100644
--- a/icu4c/source/test/cintltst/unumberformattertst.c
+++ b/icu4c/source/test/cintltst/unumberformattertst.c
@@ -76,7 +76,8 @@ static void TestSkeletonFormatToFields() {
     // setup:
     UNumberFormatter* uformatter = unumf_openFromSkeletonAndLocale(
             u".00 measure-unit/length-meter sign-always", -1, "en", &ec);
-    assertSuccess("Should create without error", &ec);
+    assertSuccessCheck("Should create without error", &ec, TRUE);
+    if (U_FAILURE(ec)) { return; }
     UFormattedNumber* uresult = unumf_openResult(&ec);
     assertSuccess("Should create result without error", &ec);
     unumf_formatInt(uformatter, 9876543210L, uresult, &ec); // "+9,876,543,210.00 m"
@@ -154,7 +155,8 @@ static void TestExampleCode() {
     UErrorCode ec = U_ZERO_ERROR;
     UNumberFormatter* uformatter = unumf_openFromSkeletonAndLocale(u"round-integer", -1, "en", &ec);
     UFormattedNumber* uresult = unumf_openResult(&ec);
-    assertSuccess("There should not be a failure in the example code", &ec);
+    assertSuccessCheck("There should not be a failure in the example code", &ec, TRUE);
+    if (U_FAILURE(ec)) { return; }
 
     // Format a double:
     unumf_formatDouble(uformatter, 5142.3, uresult, &ec);
diff --git a/icu4c/source/test/intltest/numbertest_api.cpp b/icu4c/source/test/intltest/numbertest_api.cpp
index bbb2f767a1..4947af33a7 100644
--- a/icu4c/source/test/intltest/numbertest_api.cpp
+++ b/icu4c/source/test/intltest/numbertest_api.cpp
@@ -2374,7 +2374,8 @@ void NumberFormatterApiTest::localPointerCAPI() {
     // Setup:
     LocalUNumberFormatterPointer uformatter(unumf_openFromSkeletonAndLocale(u"percent", -1, "en", &ec));
     LocalUFormattedNumberPointer uresult(unumf_openResult(&ec));
-    assertSuccess("", ec);
+    assertSuccess("", ec, TRUE);
+    if (U_FAILURE(ec)) { return; }
 
     // Format a decimal number:
     unumf_formatDecimal(uformatter.getAlias(), "9.87E-3", -1, uresult.getAlias(), &ec);