diff --git a/src/co2.js b/src/co2.js
index db8f598..894ef6b 100644
--- a/src/co2.js
+++ b/src/co2.js
@@ -64,10 +64,9 @@ import SustainableWebDesignV3 from "./sustainable-web-design-v3.js";
 import SustainableWebDesignV4 from "./sustainable-web-design-v4.js";
 
 import {
-  GLOBAL_GRID_INTENSITY,
-  RENEWABLES_GRID_INTENSITY,
-} from "./constants/index.js";
-import { parseOptions } from "./helpers/index.js";
+  parseByteTraceOptions,
+  parseVisitTraceOptions,
+} from "./helpers/index.js";
 
 class CO2 {
   constructor(options) {
@@ -152,7 +151,11 @@ class CO2 {
    * @return {CO2EstimateTraceResultPerByte} the amount of CO2 in grammes
    */
   perByteTrace(bytes, green = false, options = {}) {
-    const adjustments = parseOptions(options, this.model.version, green);
+    const adjustments = parseByteTraceOptions(
+      options,
+      this.model.version,
+      green
+    );
 
     // Filter out the trace items that aren't relevant to this function.
     const { gridIntensity, ...traceVariables } = adjustments;
@@ -197,7 +200,11 @@ class CO2 {
    */
   perVisitTrace(bytes, green = false, options = {}) {
     if (this.model?.perVisit) {
-      const adjustments = parseOptions(options, this.model.version, green);
+      const adjustments = parseVisitTraceOptions(
+        options,
+        this.model.version,
+        green
+      );
       const { gridIntensity, ...variables } = adjustments;
 
       return {
diff --git a/src/helpers/index.js b/src/helpers/index.js
index 8ff63f9..cdc13df 100644
--- a/src/helpers/index.js
+++ b/src/helpers/index.js
@@ -23,7 +23,7 @@ const formatNumber = (num) => parseFloat(num.toFixed(2));
 
 const lessThanEqualTo = (num, limit) => num <= limit;
 
-function parseOptions(options = {}, version = 3, green = false) {
+function parseByteTraceOptions(options = {}, version = 3, green = false) {
   const globalGridIntensity =
     version === 4 ? SWDM4_GLOBAL_GRID_INTENSITY : SWDM3_GLOBAL_GRID_INTENSITY;
   // CHeck that it is an object
@@ -131,6 +131,44 @@ function parseOptions(options = {}, version = 3, green = false) {
     };
   }
 
+  if (
+    options?.greenHostingFactor ||
+    (options.greenHostingFactor === 0 && version === 4)
+  ) {
+    if (typeof options.greenHostingFactor === "number") {
+      if (options.greenHostingFactor >= 0 && options.greenHostingFactor <= 1) {
+        adjustments.greenHostingFactor = options.greenHostingFactor;
+      } else {
+        adjustments.greenHostingFactor = 0;
+        console.warn(
+          `The returnVisitPercentage option must be a number between 0 and 1. You passed in ${options.returnVisitPercentage}. \nFalling back to default value.`
+        );
+      }
+    } else {
+      adjustments.greenHostingFactor = 0;
+      console.warn(
+        `The returnVisitPercentage option must be a number. You passed in a ${typeof options.returnVisitPercentage}. \nFalling back to default value.`
+      );
+    }
+  } else if (version === 4) {
+    adjustments.greenHostingFactor = 0;
+  }
+
+  if (green) {
+    adjustments.greenHostingFactor = 1;
+  }
+
+  return adjustments;
+}
+
+function parseVisitTraceOptions(options = {}, version = 3, green = false) {
+  // CHeck that it is an object
+  if (typeof options !== "object") {
+    throw new Error("Options must be an object");
+  }
+
+  const adjustments = parseByteTraceOptions(options, version, green);
+
   if (options?.dataReloadRatio || options.dataReloadRatio === 0) {
     if (typeof options.dataReloadRatio === "number") {
       if (options.dataReloadRatio >= 0 && options.dataReloadRatio <= 1) {
@@ -215,33 +253,6 @@ function parseOptions(options = {}, version = 3, green = false) {
     );
   }
 
-  if (
-    options?.greenHostingFactor ||
-    (options.greenHostingFactor === 0 && version === 4)
-  ) {
-    if (typeof options.greenHostingFactor === "number") {
-      if (options.greenHostingFactor >= 0 && options.greenHostingFactor <= 1) {
-        adjustments.greenHostingFactor = options.greenHostingFactor;
-      } else {
-        adjustments.greenHostingFactor = 0;
-        console.warn(
-          `The returnVisitPercentage option must be a number between 0 and 1. You passed in ${options.returnVisitPercentage}. \nFalling back to default value.`
-        );
-      }
-    } else {
-      adjustments.greenHostingFactor = 0;
-      console.warn(
-        `The returnVisitPercentage option must be a number. You passed in a ${typeof options.returnVisitPercentage}. \nFalling back to default value.`
-      );
-    }
-  } else if (version === 4) {
-    adjustments.greenHostingFactor = 0;
-  }
-
-  if (green) {
-    adjustments.greenHostingFactor = 1;
-  }
-
   return adjustments;
 }
 
@@ -299,7 +310,8 @@ function outputRating(co2e, swdmVersion) {
 
 export {
   formatNumber,
-  parseOptions,
+  parseByteTraceOptions,
+  parseVisitTraceOptions,
   getApiRequestHeaders,
   lessThanEqualTo,
   outputRating,