diff --git a/gsrs-module-substance-example/src/test/java/example/substance/processor/UniqueCodeGeneratorTest.java b/gsrs-module-substance-example/src/test/java/example/substance/processor/UniqueCodeGeneratorTest.java
index 4a05ae9b..ace2a77f 100644
--- a/gsrs-module-substance-example/src/test/java/example/substance/processor/UniqueCodeGeneratorTest.java
+++ b/gsrs-module-substance-example/src/test/java/example/substance/processor/UniqueCodeGeneratorTest.java
@@ -183,7 +183,8 @@ public void testSeqGenCheckDefaults() {
         CodeSequentialGenerator codeGenerator = new CodeSequentialGenerator(seqGenName, length, suffix, padding, max, codeSystem, null);
         ProteinSubstance substance = getSubstanceFromFile("YYD6UT8T47");
         AutowireHelper.getInstance().autowire(codeGenerator);
-        assertEquals(codeGenerator.getMax(), codeGenerator.DEFAULT_MAX);
+        assertEquals(codeGenerator.getMax(), (Long) Long.MAX_VALUE);
+
         assertEquals(codeGenerator.getLen(),String.valueOf(codeGenerator.getMax()).length()+codeGenerator.getSuffix().length());
     }
 
diff --git a/gsrs-module-substances-core/src/main/java/gsrs/module/substance/processors/UniqueCodeGenerator.java b/gsrs-module-substances-core/src/main/java/gsrs/module/substance/processors/UniqueCodeGenerator.java
index 2b02ce12..6256f2a7 100644
--- a/gsrs-module-substances-core/src/main/java/gsrs/module/substance/processors/UniqueCodeGenerator.java
+++ b/gsrs-module-substances-core/src/main/java/gsrs/module/substance/processors/UniqueCodeGenerator.java
@@ -15,6 +15,7 @@
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -37,8 +38,8 @@ public UniqueCodeGenerator(Map with) {
         log.trace("UniqueCodeGenerator constructor with Map");
         String name = (String) with.get("name");
         codeSystem = (String) with.get("codesystem");
-        String codeSystemSuffix = (String) with.get("suffix");
-        int length = (Integer) with.get("length");
+        String codeSystemSuffix = (String) with.getOrDefault("suffix", "");
+        int length = (int) with.getOrDefault("length", 0);
         boolean padding = (Boolean) with.get("padding");
         Boolean useLegacy = (Boolean) with.get("useLegacy");
         Map<Integer, String> groups = (Map<Integer, String>) with.get("groups");
@@ -46,7 +47,8 @@ public UniqueCodeGenerator(Map with) {
         try {
             maxValue = Long.parseLong(String.valueOf(with.get("max")));
         } catch (Exception e) {
-            maxValue = Long.MAX_VALUE;
+            int counterLen = length - codeSystemSuffix.length();
+            maxValue = counterLen < 1 ? Long.MAX_VALUE : Long.valueOf(String.join("", Collections.nCopies(counterLen, "9")));
         }
         final Long max = maxValue;
         String msg = String.format("codeSystem: %s; codeSystemSuffix: %s; length: %d;  padding: %b, max: %d",
diff --git a/gsrs-module-substances-core/src/main/java/ix/ginas/utils/CodeSequentialGenerator.java b/gsrs-module-substances-core/src/main/java/ix/ginas/utils/CodeSequentialGenerator.java
index 61aa5d82..ad000a3f 100644
--- a/gsrs-module-substances-core/src/main/java/ix/ginas/utils/CodeSequentialGenerator.java
+++ b/gsrs-module-substances-core/src/main/java/ix/ginas/utils/CodeSequentialGenerator.java
@@ -13,6 +13,7 @@
 import ix.ginas.models.v1.Substance;
 import lombok.extern.slf4j.Slf4j;
 
+import java.util.Collections;
 import java.util.Map;
 import java.util.Objects;
 /*
@@ -49,8 +50,6 @@
 @Component
 public class CodeSequentialGenerator extends SequentialNumericIDGenerator<Substance> {
 
-	public static final Long DEFAULT_MAX = Long.MAX_VALUE;
-
 	@Autowired
 	private CodeRepository codeRepository;
 
@@ -88,10 +87,12 @@ public CodeSequentialGenerator( @JsonProperty("name") String name,
 					@JsonProperty("groups") Map<Integer, String> groups) {
 
 		super(len, suffix, padding);
-		if(max==null) { max=DEFAULT_MAX; }
-
-		this.max = max;
 		if(suffix==null) { this.suffix= "";}
+		if(max==null) {
+			int counterLen = len - this.suffix.length();
+			max = counterLen < 1 ? Long.MAX_VALUE : Long.valueOf(String.join("", Collections.nCopies(counterLen, "9")));
+		}
+		this.max = max;
 		this.groups = (groups != null) ? groups.values().stream().toArray(String[]::new) : null;
 		if(!this.getClass().equals(LegacyCodeSequentialGenerator.class)) {
             // Legacy could be an extension of this class, and if so these checks aren't appropriate.