diff --git a/icu4c/source/common/ucnv_bld.c b/icu4c/source/common/ucnv_bld.c
index cef35198c99..861a57e8043 100644
--- a/icu4c/source/common/ucnv_bld.c
+++ b/icu4c/source/common/ucnv_bld.c
@@ -529,7 +529,6 @@ ucnv_createConverter(UConverter *myUConverter, const char *converterName, UError
     UConverterSharedData *mySharedConverterData = NULL;
     UErrorCode internalErrorCode = U_ZERO_ERROR;
     uint32_t options = 0;
-    int32_t cnvNumber = -1;
     if (U_FAILURE (*err))
         return NULL;
 
@@ -552,7 +551,7 @@ ucnv_createConverter(UConverter *myUConverter, const char *converterName, UError
         }
 
         /* get the canonical converter name */
-        realName = ucnv_io_getConverterName(cnvName, &cnvNumber, &internalErrorCode);
+        realName = ucnv_io_getConverterName(cnvName, &internalErrorCode);
         if (U_FAILURE(internalErrorCode) || realName == NULL) {
             /*
             * set the input name in case the converter was added
diff --git a/icu4c/source/common/ucnv_io.c b/icu4c/source/common/ucnv_io.c
index 1d0a582a114..b669e3c5a82 100644
--- a/icu4c/source/common/ucnv_io.c
+++ b/icu4c/source/common/ucnv_io.c
@@ -574,20 +574,14 @@ findTaggedConverterNum(const char *alias, const char *standard, UErrorCode *pErr
 
 
 U_CFUNC const char *
-ucnv_io_getConverterName(const char *alias, int32_t *convNumPtr, UErrorCode *pErrorCode) {
+ucnv_io_getConverterName(const char *alias, UErrorCode *pErrorCode) {
     if(haveAliasData(pErrorCode) && isAlias(alias, pErrorCode)) {
         uint32_t convNum = findConverter(alias, pErrorCode);
         if (convNum < gConverterListSize) {
-            if (convNumPtr) {
-                *convNumPtr = (int32_t)convNum;
-            }
             return GET_STRING(gConverterList[convNum]);
         }
         /* else converter not found */
     }
-    if (convNumPtr) {
-        *convNumPtr = -1;
-    }
     return NULL;
 }
 
@@ -1024,7 +1018,7 @@ ucnv_io_setDefaultConverterName(const char *converterName) {
         gDefaultConverterName=NULL;
     } else {
         UErrorCode errorCode=U_ZERO_ERROR;
-        const char *name=ucnv_io_getConverterName(converterName, NULL, &errorCode);
+        const char *name=ucnv_io_getConverterName(converterName, &errorCode);
         if(U_SUCCESS(errorCode) && name!=NULL) {
             gDefaultConverterName=name;
         } else {
diff --git a/icu4c/source/common/ucnv_io.h b/icu4c/source/common/ucnv_io.h
index 5bb471e7219..a236f5b0a0a 100644
--- a/icu4c/source/common/ucnv_io.h
+++ b/icu4c/source/common/ucnv_io.h
@@ -36,12 +36,11 @@ ucnv_io_stripForCompare(char *dst, const char *name);
  * is returned in mixed-case.
  * Returns NULL if the alias is not found.
  * @param alias The alias name to be searched.
- * @param convNumPtr aAn out param for the index of the converter name in the alias table.
  * @param pErrorCode The error code
  * @return the converter name in mixed-case, return NULL if the alias is not found.
  */
 U_CFUNC const char *
-ucnv_io_getConverterName(const char *alias, int32_t *convNumPtr, UErrorCode *pErrorCode);
+ucnv_io_getConverterName(const char *alias, UErrorCode *pErrorCode);
 
 /**
  * The count for ucnv_io_getAliases and ucnv_io_getAlias