diff --git a/src/services/express_request.rs b/src/services/express_request.rs
index dc8732de6..7721f9744 100644
--- a/src/services/express_request.rs
+++ b/src/services/express_request.rs
@@ -32,6 +32,10 @@ pub struct MpesaExpressRequest<'mpesa> {
     pub timestamp: DateTime<Local>,
     /// This is the transaction type that is used to identify the transaction
     /// when sending the request to M-PESA
+    ///
+    /// The TransactionType for Mpesa Express is either
+    /// `CommandId::BusinessBuyGoods` or
+    /// `CommandId::CustomerPayBillOnline`
     pub transaction_type: CommandId,
     /// This is the Amount transacted normally a numeric value
     pub amount: f64,
@@ -99,20 +103,45 @@ pub struct MpesaExpressResponse {
 pub struct MpesaExpress<'mpesa, Env: ApiEnvironment> {
     #[builder(pattern = "immutable")]
     client: &'mpesa Mpesa<Env>,
+    /// This is the organization's shortcode (Paybill or Buygoods - A 5 to
+    /// 6-digit account number) used to identify an organization and receive
+    /// the transaction.
     #[builder(setter(into))]
     business_short_code: &'mpesa str,
+    /// This is the transaction type that is used to identify the transaction
+    /// when sending the request to M-PESA
+    ///
+    /// The TransactionType for Mpesa Express is either
+    /// `CommandId::BusinessBuyGoods` or
+    /// `CommandId::CustomerPayBillOnline`
     transaction_type: CommandId,
+    /// This is the Amount transacted normally a numeric value
     #[builder(setter(into))]
     amount: f64,
+    /// The phone number sending money.
     party_a: &'mpesa str,
+    /// The organization that receives the funds
     party_b: &'mpesa str,
+    /// The Mobile Number to receive the STK Pin Prompt.
     phone_number: &'mpesa str,
+    /// A CallBack URL is a valid secure URL that is used to receive
+    /// notifications from M-Pesa API.
+    /// It is the endpoint to which the results will be sent by M-Pesa API.
     #[builder(try_setter, setter(into))]
     callback_url: Url,
+    /// Account Reference: This is an Alpha-Numeric parameter that is defined
+    /// by your system as an Identifier of the transaction for
+    /// CustomerPayBillOnline
     #[builder(setter(into))]
     account_ref: &'mpesa str,
+    /// This is any additional information/comment that can be sent along with
+    /// the request from your system
     #[builder(setter(into, strip_option), default)]
     transaction_desc: Option<&'mpesa str>,
+    /// This is the password used for encrypting the request sent:
+    /// The password for encrypting the request is obtained by base64 encoding
+    /// BusinessShortCode, Passkey and Timestamp.
+    /// The timestamp format is YYYYMMDDHHmmss
     #[builder(setter(into))]
     pass_key: &'mpesa str,
 }
@@ -169,6 +198,22 @@ impl<'mpesa, Env: ApiEnvironment> MpesaExpress<'mpesa, Env> {
         MpesaExpressBuilder::default().client(client)
     }
 
+    /// Encodes the password for the request
+    /// The password for encrypting the request is obtained by base64 encoding
+    /// BusinessShortCode, Passkey and Timestamp.
+    /// The timestamp format is YYYYMMDDHHmmss
+    pub fn encode_password(business_short_code: &str, pass_key: Option<&'mpesa str>) -> String {
+        base64::encode_block(
+            format!(
+                "{}{}{}",
+                business_short_code,
+                pass_key.unwrap_or(DEFAULT_PASSKEY),
+                chrono::Local::now()
+            )
+            .as_bytes(),
+        )
+    }
+
     /// Creates a new `MpesaExpress` from a `MpesaExpressRequest`
     pub fn from_request(
         client: &'mpesa Mpesa<Env>,
diff --git a/tests/mpesa-rust/stk_push_test.rs b/tests/mpesa-rust/stk_push_test.rs
index ce6b6f952..e843f9f19 100644
--- a/tests/mpesa-rust/stk_push_test.rs
+++ b/tests/mpesa-rust/stk_push_test.rs
@@ -1,8 +1,11 @@
+use mpesa::services::{MpesaExpress, MpesaExpressRequest};
+use mpesa::CommandId;
 use serde_json::json;
 use wiremock::matchers::{method, path};
 use wiremock::{Mock, ResponseTemplate};
 
 use crate::get_mpesa_client;
+use crate::helpers::TestEnvironment;
 
 #[tokio::test]
 async fn stk_push_success() {
@@ -86,3 +89,54 @@ async fn stk_push_only_accepts_specific_tx_type() {
         "Invalid transaction type. Expected BusinessBuyGoods or CustomerPayBillOnline"
     );
 }
+
+#[tokio::test]
+async fn express_request_test_using_struct_initialization() {
+    let (client, server) = get_mpesa_client!();
+
+    let sample_response_body = json!({
+        "MerchantRequestID": "16813-1590513-1",
+        "CheckoutRequestID": "ws_CO_DMZ_12321_23423476",
+        "ResponseDescription": "Accept the service request successfully.",
+        "ResponseCode": "0",
+        "CustomerMessage": "Success. Request accepted for processing"
+    });
+
+    let password = MpesaExpress::<TestEnvironment>::encode_password("174379", None);
+
+    let request = MpesaExpressRequest {
+        business_short_code: "174379",
+        transaction_type: CommandId::BusinessBuyGoods,
+        amount: 500.0,
+        party_a: "254708374149",
+        party_b: "174379",
+        phone_number: "254708374149",
+        password,
+        timestamp: chrono::Local::now(),
+        call_back_url: "https://test.example.com/api".try_into().unwrap(),
+        account_reference: "test",
+        transaction_desc: None,
+    };
+
+    Mock::given(method("POST"))
+        .and(path("/mpesa/stkpush/v1/processrequest"))
+        .respond_with(ResponseTemplate::new(200).set_body_json(sample_response_body))
+        .expect(1)
+        .mount(&server)
+        .await;
+
+    let request = MpesaExpress::from_request(&client, request, None);
+
+    let response = request.send().await.unwrap();
+
+    assert_eq!(response.merchant_request_id, "16813-1590513-1");
+    assert_eq!(response.checkout_request_id, "ws_CO_DMZ_12321_23423476");
+    assert_eq!(
+        response.response_description,
+        "Accept the service request successfully."
+    );
+    assert_eq!(
+        response.customer_message,
+        "Success. Request accepted for processing"
+    );
+}