diff --git a/src/main/java/com/cringe_studios/cringe_authenticator_library/OTP.java b/src/main/java/com/cringe_studios/cringe_authenticator_library/OTP.java
index 22cf386..5c8aadd 100644
--- a/src/main/java/com/cringe_studios/cringe_authenticator_library/OTP.java
+++ b/src/main/java/com/cringe_studios/cringe_authenticator_library/OTP.java
@@ -50,7 +50,9 @@ public abstract class OTP {
 	
 	public abstract long getNextDueTime();
 	
-	public abstract String getPin();
+	public abstract String getPin() throws OTPException;
+	
+	public abstract void incrementCounter();
 	
 	public String getSecret() {
 		return this.base32Secret;
diff --git a/src/main/java/com/cringe_studios/cringe_authenticator_library/OTPException.java b/src/main/java/com/cringe_studios/cringe_authenticator_library/OTPException.java
new file mode 100644
index 0000000..c84162c
--- /dev/null
+++ b/src/main/java/com/cringe_studios/cringe_authenticator_library/OTPException.java
@@ -0,0 +1,26 @@
+package com.cringe_studios.cringe_authenticator_library;
+
+public class OTPException extends RuntimeException {
+
+	private static final long serialVersionUID = 4635395862998258574L;
+
+	public OTPException() {
+	}
+
+	public OTPException(String message) {
+		super(message);
+	}
+
+	public OTPException(Throwable cause) {
+		super(cause);
+	}
+
+	public OTPException(String message, Throwable cause) {
+		super(message, cause);
+	}
+
+	public OTPException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
+		super(message, cause, enableSuppression, writableStackTrace);
+	}
+
+}
diff --git a/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/HOTP.java b/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/HOTP.java
index 56a4bcd..eb61468 100644
--- a/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/HOTP.java
+++ b/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/HOTP.java
@@ -1,16 +1,11 @@
 package com.cringe_studios.cringe_authenticator_library.impl;
 
-import java.nio.charset.StandardCharsets;
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
 
-import javax.crypto.Mac;
-import javax.crypto.MacSpi;
-import javax.crypto.spec.SecretKeySpec;
-import javax.xml.crypto.dsig.spec.HMACParameterSpec;
-
 import com.cringe_studios.cringe_authenticator_library.OTP;
 import com.cringe_studios.cringe_authenticator_library.OTPAlgorithm;
+import com.cringe_studios.cringe_authenticator_library.OTPException;
 import com.cringe_studios.cringe_authenticator_library.OTPType;
 
 //https://datatracker.ietf.org/doc/html/rfc4226
@@ -30,7 +25,7 @@ public class HOTP extends OTP {
 	}
 
 	@Override
-	public String getPin() {
+	public String getPin() throws OTPException{
 		try {
 			long movingFactor = this.getCounter();
 			
@@ -41,14 +36,12 @@ public class HOTP extends OTP {
 			}
 			
 			return generateOTP(-1, text);
+			
 		} catch (InvalidKeyException e) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
+			throw new OTPException("Your secret is invalid! Please rescan the code!", e);
 		} catch (NoSuchAlgorithmException e) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
+			throw new OTPException("Your platform does not support the " + this.getAlgorithm().name() + "algorithm!", e);
 		}
-		return null;
 	}
 
 	public String generateOTP(int truncationOffset, byte[] message) throws NoSuchAlgorithmException, InvalidKeyException {
@@ -84,4 +77,9 @@ public class HOTP extends OTP {
 		return result;
 	}
 
+	@Override
+	public void incrementCounter() {
+		this.counter++;
+	}
+
 }
diff --git a/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/InvalidBase32Exception.java b/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/InvalidBase32Exception.java
new file mode 100644
index 0000000..a7100fc
--- /dev/null
+++ b/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/InvalidBase32Exception.java
@@ -0,0 +1,5 @@
+package com.cringe_studios.cringe_authenticator_library.impl;
+
+public class InvalidBase32Exception extends IllegalArgumentException {
+	private static final long serialVersionUID = 8747632785152793756L;
+}
diff --git a/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/TOTP.java b/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/TOTP.java
index e71aeee..9669882 100644
--- a/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/TOTP.java
+++ b/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/TOTP.java
@@ -1,15 +1,12 @@
 package com.cringe_studios.cringe_authenticator_library.impl;
 
-import java.math.BigInteger;
 import java.nio.ByteBuffer;
-import java.nio.charset.Charset;
-import java.nio.charset.StandardCharsets;
 import java.security.InvalidKeyException;
 import java.security.NoSuchAlgorithmException;
 import java.time.Instant;
 
-import com.cringe_studios.cringe_authenticator_library.OTP;
 import com.cringe_studios.cringe_authenticator_library.OTPAlgorithm;
+import com.cringe_studios.cringe_authenticator_library.OTPException;
 import com.cringe_studios.cringe_authenticator_library.OTPType;
 
 //https://datatracker.ietf.org/doc/html/rfc6238
@@ -22,24 +19,20 @@ public class TOTP extends HOTP {
 	
 	@Override
 	public long getNextDueTime() {
-		// TODO Auto-generated method stub
 		// e.g. current time: 20 seconds & current period: 30 seconds -> next due time:
 		// 30 seconds
 		return (this.getCounter() + 1) * this.getPeriod();
 	}
 
 	@Override
-	public String getPin() {
-		// TODO Auto-generated method stub
+	public String getPin() throws OTPException{
 		try {
 			return getPinAt(Instant.now().getEpochSecond());
 		} catch (InvalidKeyException e) {
-			e.printStackTrace();
+			throw new OTPException("Your secret is invalid! Please rescan the code!", e);
 		} catch (NoSuchAlgorithmException e) {
-			e.printStackTrace();
+			throw new OTPException("Your platform does not support the " + this.getAlgorithm().name() + "algorithm!", e);
 		}
-		
-		return null;
 	}
 
 	@Override
@@ -75,4 +68,7 @@ public class TOTP extends HOTP {
 		
 		return this.generateOTP(-1, msg);
 	}
+	
+	@Override
+	public void incrementCounter() {}
 }
\ No newline at end of file