diff --git a/common/nym_offline_compact_ecash/src/scheme/mod.rs b/common/nym_offline_compact_ecash/src/scheme/mod.rs
index 281cf7d984..53d3b73bea 100644
--- a/common/nym_offline_compact_ecash/src/scheme/mod.rs
+++ b/common/nym_offline_compact_ecash/src/scheme/mod.rs
@@ -433,6 +433,19 @@ impl Payment {
         Ok(true)
     }
 
+    pub fn serial_number_bs58(&self) -> String {
+        SerialNumber {
+            inner: self.ss.clone(),
+        }
+        .to_bs58()
+    }
+
+    pub fn has_serial_number(&self, serial_number_bs58: &str) -> Result<bool> {
+        let serial_number = SerialNumber::try_from_bs58(serial_number_bs58)?;
+        let ret = self.ss.eq(&serial_number.inner);
+        Ok(ret)
+    }
+
     pub fn to_bytes(&self) -> Vec<u8> {
         let kappa_bytes = self.kappa.to_affine().to_compressed();
         let sig_bytes = self.sig.to_bytes();
@@ -640,6 +653,60 @@ impl TryFrom<&[u8]> for Payment {
     }
 }
 
+pub struct SerialNumber {
+    pub(crate) inner: Vec<G1Projective>,
+}
+
+impl SerialNumber {
+    pub fn to_bytes(&self) -> Vec<u8> {
+        let ss_len = self.inner.len();
+        let mut bytes: Vec<u8> = Vec::with_capacity(ss_len * 48);
+        for s in &self.inner {
+            bytes.extend_from_slice(&s.to_affine().to_compressed());
+        }
+        bytes
+    }
+}
+
+impl TryFrom<&[u8]> for SerialNumber {
+    type Error = CompactEcashError;
+
+    fn try_from(bytes: &[u8]) -> Result<Self> {
+        if bytes.len() % 48 != 0 {
+            return Err(
+                CompactEcashError::Deserialization(
+                    format!("Tried to deserialize blinded serial number with incorrect number of bytes, expected a multiple of 48, got {}", bytes.len()),
+                ));
+        }
+        let inner_len = bytes.len() / 48;
+        let mut inner = Vec::with_capacity(inner_len);
+        let mut idx = 0;
+        for _ in 0..inner_len {
+            let ss_bytes: [u8; 48] = bytes[idx..idx + 48].try_into().unwrap();
+            let ss_elem = try_deserialize_g1_projective(
+                &ss_bytes,
+                CompactEcashError::Deserialization("Failed to deserialize ss element".to_string()),
+            )?;
+            inner.push(ss_elem);
+            idx += 48;
+        }
+
+        Ok(SerialNumber { inner })
+    }
+}
+
+impl Bytable for SerialNumber {
+    fn to_byte_vec(&self) -> Vec<u8> {
+        self.to_bytes().to_vec()
+    }
+
+    fn try_from_byte_slice(slice: &[u8]) -> Result<Self> {
+        Self::try_from(slice)
+    }
+}
+
+impl Base58 for SerialNumber {}
+
 #[derive(Getters, CopyGetters)]
 pub struct EcashCredential {
     #[getset(get = "pub")]
@@ -677,12 +744,12 @@ impl EcashCredential {
     pub fn value(&self) -> u64 {
         self.value
     }
-    pub fn blinded_serial_number(&self) -> String {
-        todo!() //SW todo
+    pub fn serial_number(&self) -> String {
+        self.payment.serial_number_bs58()
     }
 
-    pub fn has_blinded_serial_number(&self, _blinded_serial_number_bs58: &str) -> Result<bool> {
-        todo!() //SW todo
+    pub fn has_serial_number(&self, serial_number_bs58: &str) -> Result<bool> {
+        self.payment.has_serial_number(serial_number_bs58)
     }
 }
 
diff --git a/gateway/src/node/client_handling/websocket/connection_handler/coconut.rs b/gateway/src/node/client_handling/websocket/connection_handler/coconut.rs
index c0978a4d28..dfc8f545a3 100644
--- a/gateway/src/node/client_handling/websocket/connection_handler/coconut.rs
+++ b/gateway/src/node/client_handling/websocket/connection_handler/coconut.rs
@@ -229,11 +229,8 @@ impl EcashVerifier {
         let res = self
             .nyxd_client
             .spend_credential(
-                Coin::new(
-                    credential.value().into(), //SW THIS WILL BE A FIXED VALUE?
-                    self.mix_denom_base.clone(),
-                ),
-                credential.blinded_serial_number(), //SW what will this be?
+                Coin::new(credential.value().into(), self.mix_denom_base.clone()),
+                credential.serial_number(),
                 self.nyxd_client.address().to_string(),
                 None,
             )
@@ -249,8 +246,7 @@ impl EcashVerifier {
             })?;
 
         let proposal = self.nyxd_client.query_proposal(proposal_id).await?;
-        if !credential.has_blinded_serial_number(&proposal.description)? {
-            //SW serial number issue
+        if !credential.has_serial_number(&proposal.description)? {
             return Err(RequestHandlingError::ProposalIdError {
                 reason: String::from("proposal has different serial number"),
             });
diff --git a/nym-api/src/coconut/mod.rs b/nym-api/src/coconut/mod.rs
index fed927a27d..2c8c75de47 100644
--- a/nym-api/src/coconut/mod.rs
+++ b/nym-api/src/coconut/mod.rs
@@ -304,7 +304,7 @@ pub async fn verify_online_credential(
     // Proposal description is the blinded serial number
     if !verify_credential_body
         .credential()
-        .has_blinded_serial_number(&proposal.description)?
+        .has_serial_number(&proposal.description)?
     {
         return Err(CoconutError::IncorrectProposal {
             reason: String::from("incorrect blinded serial number in description"),
@@ -317,7 +317,7 @@ pub async fn verify_online_credential(
     // Credential has not been spent before, and is on its way of being spent
     let credential_status = state
         .client
-        .get_spent_credential(verify_credential_body.credential().blinded_serial_number())
+        .get_spent_credential(verify_credential_body.credential().serial_number())
         .await?
         .spend_credential
         .ok_or(CoconutError::InvalidCredentialStatus {
@@ -344,7 +344,6 @@ pub async fn verify_online_credential(
             CoconutError::CompactEcashInternalError(CompactEcashError::PaymentVerification)
         })?;
 
-    //SW THIS WILL HAVE TO CHANGE AS WELL
     vote_yes &= Coin::from(proposed_release_funds)
         == Coin::new(
             verify_credential_body.credential().value() as u128,