diff --git a/integration-tests/modules/__tests__/cart/store/cart.workflows.spec.ts b/integration-tests/modules/__tests__/cart/store/cart.workflows.spec.ts
index 9c10a9ac4aaee..044ba62b7e30a 100644
--- a/integration-tests/modules/__tests__/cart/store/cart.workflows.spec.ts
+++ b/integration-tests/modules/__tests__/cart/store/cart.workflows.spec.ts
@@ -1,5 +1,5 @@
 import {
-  addShippingMethodToWorkflow,
+  addShippingMethodToCartWorkflow,
   addToCartWorkflow,
   createCartWorkflow,
   createPaymentCollectionForCartWorkflow,
@@ -1638,22 +1638,7 @@ medusaIntegrationTestRunner({
             },
           ])
 
-          await addShippingMethodToWorkflow(appContainer).run({
-            input: {
-              options: [{ id: shippingOption.id }],
-              cart_id: cart.id,
-            },
-          })
-
-          await addShippingMethodToWorkflow(appContainer).run({
-            input: {
-              options: [{ id: shippingOption.id }],
-              cart_id: cart.id,
-            },
-          })
-
-          // should remove the previous shipping method
-          await addShippingMethodToWorkflow(appContainer).run({
+          await addShippingMethodToCartWorkflow(appContainer).run({
             input: {
               options: [{ id: shippingOption.id }],
               cart_id: cart.id,
@@ -1707,7 +1692,7 @@ medusaIntegrationTestRunner({
             },
           ])
 
-          const { errors } = await addShippingMethodToWorkflow(
+          const { errors } = await addShippingMethodToCartWorkflow(
             appContainer
           ).run({
             input: {
@@ -1729,7 +1714,7 @@ medusaIntegrationTestRunner({
         })
 
         it("should throw error when shipping option is not present in the db", async () => {
-          const { errors } = await addShippingMethodToWorkflow(
+          const { errors } = await addShippingMethodToCartWorkflow(
             appContainer
           ).run({
             input: {
@@ -1749,6 +1734,103 @@ medusaIntegrationTestRunner({
             }),
           ])
         })
+
+        it("should add shipping method with custom data", async () => {
+          const stockLocation = (
+            await api.post(
+              `/admin/stock-locations`,
+              { name: "test location" },
+              adminHeaders
+            )
+          ).data.stock_location
+
+          await remoteLink.create([
+            {
+              [Modules.STOCK_LOCATION]: {
+                stock_location_id: stockLocation.id,
+              },
+              [Modules.FULFILLMENT]: {
+                fulfillment_set_id: fulfillmentSet.id,
+              },
+            },
+          ])
+
+          await api.post(
+            `/admin/stock-locations/${stockLocation.id}/fulfillment-providers`,
+            { add: ["manual_test-provider"] },
+            adminHeaders
+          )
+
+          const shippingOption = await fulfillmentModule.createShippingOptions({
+            name: "Test shipping option",
+            service_zone_id: fulfillmentSet.service_zones[0].id,
+            shipping_profile_id: shippingProfile.id,
+            provider_id: "manual_test-provider",
+            price_type: "flat",
+            type: {
+              label: "Test type",
+              description: "Test description",
+              code: "test-code",
+            },
+            rules: [
+              {
+                operator: RuleOperator.EQ,
+                attribute: "is_return",
+                value: "false",
+              },
+              {
+                operator: RuleOperator.EQ,
+                attribute: "enabled_in_store",
+                value: "true",
+              },
+            ],
+          })
+
+          await remoteLink.create([
+            {
+              [Modules.FULFILLMENT]: { shipping_option_id: shippingOption.id },
+              [Modules.PRICING]: { price_set_id: priceSet.id },
+            },
+          ])
+
+          await addShippingMethodToCartWorkflow(appContainer).run({
+            input: {
+              options: [{ id: shippingOption.id, data: { test: "test" } }],
+              cart_id: cart.id,
+            },
+          })
+
+          cart = await cartModuleService.retrieveCart(cart.id, {
+            select: ["id"],
+            relations: ["shipping_methods"],
+          })
+
+          expect(cart).toEqual(
+            expect.objectContaining({
+              id: cart.id,
+              shipping_methods: [
+                {
+                  id: expect.any(String),
+                  cart_id: cart.id,
+                  description: null,
+                  amount: 3000,
+                  raw_amount: {
+                    value: "3000",
+                    precision: 20,
+                  },
+                  metadata: null,
+                  is_tax_inclusive: true,
+                  name: "Test shipping option",
+                  data: { test: "test" },
+                  shipping_option_id: shippingOption.id,
+                  deleted_at: null,
+                  updated_at: expect.any(Date),
+                  created_at: expect.any(Date),
+                },
+              ],
+            })
+          )
+        })
       })
 
       describe("listShippingOptionsForCartWorkflow", () => {
diff --git a/packages/core/core-flows/src/cart/steps/validate-shipping-methods-data.ts b/packages/core/core-flows/src/cart/steps/validate-shipping-methods-data.ts
new file mode 100644
index 0000000000000..eec94e9f8730e
--- /dev/null
+++ b/packages/core/core-flows/src/cart/steps/validate-shipping-methods-data.ts
@@ -0,0 +1,50 @@
+import { Modules, promiseAll } from "@medusajs/framework/utils"
+import { IFulfillmentModuleService } from "@medusajs/types"
+import { createStep, StepResponse } from "@medusajs/workflows-sdk"
+
+export interface ValidateShippingMethodsDataInput {
+  context: Record<string, unknown>
+  options_to_validate: {
+    id: string
+    provider_id: string
+    option_data: Record<string, unknown>
+    method_data: Record<string, unknown>
+  }[]
+}
+
+export const validateAndReturnShippingMethodsDataStepId =
+  "validate-and-return-shipping-methods-data"
+/**
+ * This step validates shipping options to ensure they can be applied on a cart.
+ */
+export const validateAndReturnShippingMethodsDataStep = createStep(
+  validateAndReturnShippingMethodsDataStepId,
+  async (data: ValidateShippingMethodsDataInput, { container }) => {
+    const { options_to_validate = [] } = data
+
+    if (!options_to_validate.length) {
+      return new StepResponse(void 0)
+    }
+
+    const fulfillmentModule = container.resolve<IFulfillmentModuleService>(
+      Modules.FULFILLMENT
+    )
+
+    const validatedData = await promiseAll(
+      options_to_validate.map(async (option) => {
+        const validated = await fulfillmentModule.validateFulfillmentData(
+          option.provider_id,
+          option.option_data,
+          option.method_data,
+          data.context
+        )
+
+        return {
+          [option.id]: validated,
+        }
+      })
+    )
+
+    return new StepResponse(validatedData)
+  }
+)
diff --git a/packages/core/core-flows/src/cart/workflows/add-shipping-method-to-cart.ts b/packages/core/core-flows/src/cart/workflows/add-shipping-method-to-cart.ts
index 49c519f18f0fc..5f7519bd735d6 100644
--- a/packages/core/core-flows/src/cart/workflows/add-shipping-method-to-cart.ts
+++ b/packages/core/core-flows/src/cart/workflows/add-shipping-method-to-cart.ts
@@ -12,6 +12,7 @@ import {
   validateCartShippingOptionsStep,
 } from "../steps"
 import { validateCartStep } from "../steps/validate-cart"
+import { validateAndReturnShippingMethodsDataStep } from "../steps/validate-shipping-methods-data"
 import { cartFieldsForRefreshSteps } from "../utils/fields"
 import { updateCartPromotionsWorkflow } from "./update-cart-promotions"
 import { updateTaxLinesWorkflow } from "./update-tax-lines"
@@ -28,7 +29,7 @@ export const addShippingMethodToCartWorkflowId = "add-shipping-method-to-cart"
 /**
  * This workflow adds shipping methods to a cart.
  */
-export const addShippingMethodToWorkflow = createWorkflow(
+export const addShippingMethodToCartWorkflow = createWorkflow(
   addShippingMethodToCartWorkflowId,
   (
     input: WorkflowData<AddShippingMethodToCartWorkflowInput>
@@ -59,6 +60,7 @@ export const addShippingMethodToWorkflow = createWorkflow(
         "name",
         "calculated_price.calculated_amount",
         "calculated_price.is_calculated_price_tax_inclusive",
+        "provider_id",
       ],
       variables: {
         id: optionIds,
@@ -68,8 +70,30 @@ export const addShippingMethodToWorkflow = createWorkflow(
       },
     }).config({ name: "fetch-shipping-option" })
 
-    const shippingMethodInput = transform(
+    const validateShippingMethodsDataInput = transform(
       { input, shippingOptions },
+      (data) => {
+        return data.input.options.map((inputOption) => {
+          const shippingOption = data.shippingOptions.find(
+            (so) => so.id === inputOption.id
+          )
+          return {
+            id: inputOption.id,
+            provider_id: shippingOption?.provider_id,
+            option_data: shippingOption?.data ?? {},
+            method_data: inputOption.data ?? {},
+          }
+        })
+      }
+    )
+
+    const validatedMethodData = validateAndReturnShippingMethodsDataStep({
+      options_to_validate: validateShippingMethodsDataInput,
+      context: {}, // TODO: Add cart, when we have a better idea about what's appropriate to pass
+    })
+
+    const shippingMethodInput = transform(
+      { input, shippingOptions, validatedMethodData },
       (data) => {
         const options = (data.input.options ?? []).map((option) => {
           const shippingOption = data.shippingOptions.find(
@@ -83,13 +107,17 @@ export const addShippingMethodToWorkflow = createWorkflow(
             )
           }
 
+          const methodData = data.validatedMethodData?.find((methodData) => {
+            return methodData?.[option.id]
+          })
+
           return {
             shipping_option_id: shippingOption.id,
             amount: shippingOption.calculated_price.calculated_amount,
             is_tax_inclusive:
               !!shippingOption.calculated_price
                 .is_calculated_price_tax_inclusive,
-            data: option.data ?? {},
+            data: methodData?.[option.id] ?? {},
             name: shippingOption.name,
             cart_id: data.input.cart_id,
           }
diff --git a/packages/core/types/src/fulfillment/service.ts b/packages/core/types/src/fulfillment/service.ts
index 736435194d74f..a0642822ebdab 100644
--- a/packages/core/types/src/fulfillment/service.ts
+++ b/packages/core/types/src/fulfillment/service.ts
@@ -2572,6 +2572,38 @@ export interface IFulfillmentModuleService extends IModuleService {
     data: Record<string, unknown>
   ): Promise<boolean>
 
+  /**
+   * This method validates fulfillment data with the provider it belongs to.
+   *   e.g. if the shipping option requires a drop point, the data you pass to create the
+   *   shipping method must contain a drop point ID. This method can be used to
+   *   validate that.
+   *
+   * @param {string} providerId - The fulfillment provider's ID.
+   * @param {Record<string, unknown>} optionData - The fulfillment option data to validate.
+   * @param {Record<string, unknown>} data - The fulfillment data to validate.
+   * @param {Record<string, unknown>} context - The context to validate the fulfillment option data in.
+   * @returns {Promise<boolean>} Whether the fulfillment option data is valid with the specified provider.
+   *
+   * @example
+   * const isValid =
+   *   await fulfillmentModuleService.validateFulfillmentData(
+   *     "webshipper",
+   *     {
+   *       requires_drop_point: true,
+   *     },
+   *     {
+   *       drop_point_id: "dp_123",
+   *     },
+   *     {}
+   *   )
+   */
+  validateFulfillmentData(
+    providerId: string,
+    optionData: Record<string, unknown>,
+    data: Record<string, unknown>,
+    context: Record<string, unknown>
+  ): Promise<Record<string, unknown>>
+
   /**
    * This method checks whether a shipping option can be used for a specified context.
    *
diff --git a/packages/core/utils/src/fulfillment/provider.ts b/packages/core/utils/src/fulfillment/provider.ts
index 0bda8570119a7..53715f6a05043 100644
--- a/packages/core/utils/src/fulfillment/provider.ts
+++ b/packages/core/utils/src/fulfillment/provider.ts
@@ -79,14 +79,6 @@ export class AbstractFulfillmentProviderService
     return obj?.constructor?._isFulfillmentService
   }
 
-  /**
-   * @ignore
-   *
-   * @privateRemarks
-   * This method is ignored as {@link validateOption} is the one used by the Fulfillment Module.
-   */
-  static validateOptions(options: Record<any, any>): void | never {}
-
   /**
    * @ignore
    */
@@ -154,7 +146,11 @@ export class AbstractFulfillmentProviderService
    *   }
    * }
    */
-  async validateFulfillmentData(optionData, data, context): Promise<any> {
+  async validateFulfillmentData(
+    optionData: Record<string, unknown>,
+    data: Record<string, unknown>,
+    context: Record<string, unknown>
+  ): Promise<any> {
     throw Error("validateFulfillmentData must be overridden by the child class")
   }
 
@@ -175,7 +171,7 @@ export class AbstractFulfillmentProviderService
    *   }
    * }
    */
-  async validateOption(data): Promise<boolean> {
+  async validateOption(data: Record<string, unknown>): Promise<boolean> {
     throw Error("validateOption must be overridden by the child class")
   }
 
@@ -194,7 +190,7 @@ export class AbstractFulfillmentProviderService
    *   }
    * }
    */
-  async canCalculate(data): Promise<boolean> {
+  async canCalculate(data: Record<string, unknown>): Promise<boolean> {
     throw Error("canCalculate must be overridden by the child class")
   }
 
@@ -221,7 +217,11 @@ export class AbstractFulfillmentProviderService
    *   }
    * }
    */
-  async calculatePrice(optionData, data, cart): Promise<number> {
+  async calculatePrice(
+    optionData: Record<string, unknown>,
+    data: Record<string, unknown>,
+    context: Record<string, unknown>
+  ): Promise<number> {
     throw Error("calculatePrice must be overridden by the child class")
   }
 
@@ -265,7 +265,12 @@ export class AbstractFulfillmentProviderService
    *   }
    * }
    */
-  async createFulfillment(data, items, order, fulfillment): Promise<any> {
+  async createFulfillment(
+    data: object,
+    items: object[],
+    order: object | undefined,
+    fulfillment: Record<string, unknown>
+  ): Promise<any> {
     throw Error("createFulfillment must be overridden by the child class")
   }
 
@@ -285,7 +290,7 @@ export class AbstractFulfillmentProviderService
    *   }
    * }
    */
-  async cancelFulfillment(fulfillment): Promise<any> {
+  async cancelFulfillment(fulfillment: Record<string, unknown>): Promise<any> {
     throw Error("cancelFulfillment must be overridden by the child class")
   }
 
@@ -305,7 +310,7 @@ export class AbstractFulfillmentProviderService
    *   }
    * }
    */
-  async getFulfillmentDocuments(data) {
+  async getFulfillmentDocuments(data: Record<string, unknown>) {
     return []
   }
 
@@ -340,7 +345,7 @@ export class AbstractFulfillmentProviderService
    *   }
    * }
    */
-  async createReturnFulfillment(fulfillment): Promise<any> {
+  async createReturnFulfillment(fulfillment: Record<string, unknown>): Promise<any> {
     throw Error("createReturn must be overridden by the child class")
   }
 
@@ -360,7 +365,7 @@ export class AbstractFulfillmentProviderService
    *   }
    * }
    */
-  async getReturnDocuments(data) {
+  async getReturnDocuments(data: Record<string, unknown>) {
     return []
   }
 
@@ -381,7 +386,7 @@ export class AbstractFulfillmentProviderService
    * }
    *
    */
-  async getShipmentDocuments(data) {
+  async getShipmentDocuments(data: Record<string, unknown>) {
     return []
   }
 
@@ -408,7 +413,10 @@ export class AbstractFulfillmentProviderService
    *   }
    * }
    */
-  async retrieveDocuments(fulfillmentData, documentType) {
+  async retrieveDocuments(
+    fulfillmentData: Record<string, unknown>,
+    documentType: string
+  ) {
     throw Error("retrieveDocuments must be overridden by the child class")
   }
 }
diff --git a/packages/medusa/src/api/store/carts/[id]/shipping-methods/route.ts b/packages/medusa/src/api/store/carts/[id]/shipping-methods/route.ts
index df1f24f289c27..0a2a6899d8d06 100644
--- a/packages/medusa/src/api/store/carts/[id]/shipping-methods/route.ts
+++ b/packages/medusa/src/api/store/carts/[id]/shipping-methods/route.ts
@@ -1,17 +1,16 @@
-import { addShippingMethodToWorkflow } from "@medusajs/core-flows"
+import { addShippingMethodToCartWorkflow } from "@medusajs/core-flows"
 import { MedusaRequest, MedusaResponse } from "@medusajs/framework/http"
+import { HttpTypes } from "@medusajs/framework/types"
 import { refetchCart } from "../../helpers"
 import { StoreAddCartShippingMethodsType } from "../../validators"
-import { HttpTypes } from "@medusajs/framework/types"
 
 export const POST = async (
   req: MedusaRequest<StoreAddCartShippingMethodsType>,
   res: MedusaResponse<HttpTypes.StoreCartResponse>
 ) => {
-  const workflow = addShippingMethodToWorkflow(req.scope)
   const payload = req.validatedBody
 
-  await workflow.run({
+  await addShippingMethodToCartWorkflow(req.scope).run({
     input: {
       options: [{ id: payload.option_id, data: payload.data }],
       cart_id: req.params.id,
diff --git a/packages/modules/fulfillment/src/services/fulfillment-module-service.ts b/packages/modules/fulfillment/src/services/fulfillment-module-service.ts
index 1d09848f6c308..5fe4f9ecfd749 100644
--- a/packages/modules/fulfillment/src/services/fulfillment-module-service.ts
+++ b/packages/modules/fulfillment/src/services/fulfillment-module-service.ts
@@ -1927,6 +1927,20 @@ export default class FulfillmentModuleService
     )
   }
 
+  async validateFulfillmentData(
+    providerId: string,
+    optionData: Record<string, unknown>,
+    data: Record<string, unknown>,
+    context: Record<string, unknown>
+  ): Promise<Record<string, unknown>> {
+    return await this.fulfillmentProviderService_.validateFulfillmentData(
+      providerId,
+      optionData,
+      data,
+      context
+    )
+  }
+
   async validateFulfillmentOption(
     providerId: string,
     data: Record<string, unknown>