diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 50254f2388..fec6d85f6a 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -4649,6 +4649,7 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout,
 	FormatNode *n;
 	NUMProc		_Np,
 			   *Np = &_Np;
+	int			separator_len;
 
 	MemSet(Np, 0, sizeof(NUMProc));
 
@@ -4802,6 +4803,7 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout,
 	 * Locale
 	 */
 	NUM_prepare_locale(Np);
+	separator_len = strlen(Np->L_thousands_sep);
 
 	/*
 	 * Processor direct cycle
@@ -4872,6 +4874,8 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout,
 							if (IS_FILLMODE(Np->Num))
 								continue;
 						}
+						if (*Np->inout_p != ',')
+							continue;
 					}
 					break;
 
@@ -4884,10 +4888,8 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout,
 								continue;
 							else
 							{
-								int			x = strlen(Np->L_thousands_sep);
-
-								memset(Np->inout_p, ' ', x);
-								Np->inout_p += x - 1;
+								memset(Np->inout_p, ' ', separator_len);
+								Np->inout_p += separator_len - 1;
 							}
 						}
 						else
@@ -4903,7 +4905,10 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout,
 							if (IS_FILLMODE(Np->Num))
 								continue;
 						}
-						Np->inout_p += strlen(Np->L_thousands_sep) - 1;
+						if (strncmp(Np->inout_p, Np->L_thousands_sep, separator_len) == 0)
+							Np->inout_p += separator_len - 1;
+						else
+							continue;
 					}
 					break;
 
diff --git a/src/test/regress/expected/numeric.out b/src/test/regress/expected/numeric.out
index 7e55b0e293..5a365bf7e7 100644
--- a/src/test/regress/expected/numeric.out
+++ b/src/test/regress/expected/numeric.out
@@ -1946,3 +1946,36 @@ SELECT SUM((-9999)::numeric) FROM generate_series(1, 100000);
  -999900000
 (1 row)
 
+--
+-- Tests to regression test TODO item 'Fix to_number() handling for values not matching the format string'
+--
+select to_number('34,50','999,99');
+ to_number 
+-----------
+      3450
+(1 row)
+
+select to_number('34,50','999G99');
+ to_number 
+-----------
+      3450
+(1 row)
+
+select to_number('12,34','999G99');
+ to_number 
+-----------
+      1234
+(1 row)
+
+select to_number('123,000','999G');
+ to_number 
+-----------
+       123
+(1 row)
+
+select to_number('123456','999G999');
+ to_number 
+-----------
+    123456
+(1 row)
+
diff --git a/src/test/regress/sql/numeric.sql b/src/test/regress/sql/numeric.sql
index 9675b6eabf..9106812b97 100644
--- a/src/test/regress/sql/numeric.sql
+++ b/src/test/regress/sql/numeric.sql
@@ -1013,3 +1013,13 @@ select scale(-13.000000000000000);
 -- cases that need carry propagation
 SELECT SUM(9999::numeric) FROM generate_series(1, 100000);
 SELECT SUM((-9999)::numeric) FROM generate_series(1, 100000);
+
+--
+-- Tests to regression test TODO item 'Fix to_number() handling for values not matching the format string'
+--
+
+select to_number('34,50','999,99');
+select to_number('34,50','999G99');
+select to_number('12,34','999G99');
+select to_number('123,000','999G');
+select to_number('123456','999G999');