diff --git a/bin/console b/bin/console
index fc775ad..3e28b27 100755
--- a/bin/console
+++ b/bin/console
@@ -1,11 +1,11 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
-require "bundler/setup"
-require "paystack_sdk"
+require 'bundler/setup'
+require 'paystack_sdk'
 
 # You can add fixtures and/or initialization code here to make experimenting
 # with your gem easier. You can also use a different console, if you like.
 
-require "irb"
+require 'irb'
 IRB.start(__FILE__)
diff --git a/lib/paystack_sdk/client.rb b/lib/paystack_sdk/client.rb
index 514a61d..1de59e1 100644
--- a/lib/paystack_sdk/client.rb
+++ b/lib/paystack_sdk/client.rb
@@ -6,6 +6,7 @@
 require_relative "resources/transfers"
 require_relative "resources/banks"
 require_relative "resources/verification"
+require_relative "resources/charges"
 require_relative "utils/connection_utils"
 
 module PaystackSdk
@@ -121,5 +122,19 @@ def banks
     def verification
       @verification ||= Resources::Verification.new(@connection)
     end
+
+    # Provides access to the `Charges` resource.
+    #
+    # @return [PaystackSdk::Resources::Charges] An instance of the
+    #  `Charges` resource.
+    #
+    # @example
+    # ```ruby
+    #   charges = client.charges
+    #   response = charges.mobile_money(payload)
+    # ```
+    def charges
+      @charges ||= Resources::Charges.new(@connection)
+    end
   end
 end
diff --git a/lib/paystack_sdk/resources/charges.rb b/lib/paystack_sdk/resources/charges.rb
new file mode 100644
index 0000000..1920533
--- /dev/null
+++ b/lib/paystack_sdk/resources/charges.rb
@@ -0,0 +1,105 @@
+# frozen_string_literal: true
+
+require_relative "base"
+
+module PaystackSdk
+  module Resources
+    # The `Charges` resource exposes helpers for initiating and managing charges
+    # through alternative payment channels such as Mobile Money.
+    #
+    # At the moment the SDK focuses on supporting the Mobile Money channel which
+    # requires posting to the `/charge` endpoint with the customer's email,
+    # amount, currency, and the provider specific `mobile_money` payload.
+    class Charges < PaystackSdk::Resources::Base
+      MOBILE_MONEY_PROVIDERS = %w[mtn atl vod mpesa orange wave].freeze
+
+      # Initiates a Mobile Money payment.
+      #
+      # @param payload [Hash] The payload containing charge details.
+      # @option payload [String] :email Customer's email address (required)
+      # @option payload [Integer] :amount Amount in the lowest currency unit (required)
+      # @option payload [String] :currency ISO currency code (default: GHS)
+      # @option payload [String] :reference Optional reference supplied by the merchant
+      # @option payload [String] :callback_url Optional callback URL for Paystack to redirect to
+      # @option payload [Hash] :metadata Optional metadata to attach to the transaction
+      # @option payload [Hash] :mobile_money The mobile money details (required)
+      #   - :phone [String] Customer's mobile money phone number (required)
+      #   - :provider [String] Mobile money provider code (required)
+      #
+      # @return [PaystackSdk::Response] The wrapped API response.
+      # @raise [PaystackSdk::ValidationError] If the payload is invalid.
+      def mobile_money(payload)
+        validate_mobile_money_payload!(payload)
+
+        normalized_payload = normalize_mobile_money_provider(payload)
+        response = @connection.post("/charge", normalized_payload)
+        handle_response(response)
+      end
+
+      # Submits an OTP for authorising a pending Mobile Money charge (e.g. Vodafone).
+      #
+      # @param payload [Hash] Payload containing the OTP and charge reference.
+      # @option payload [String] :otp The OTP supplied by the customer (required)
+      # @option payload [String] :reference The charge reference returned from initiation (required)
+      #
+      # @return [PaystackSdk::Response] The wrapped API response.
+      # @raise [PaystackSdk::ValidationError] If the payload is invalid.
+      def submit_otp(payload)
+        validate_fields!(
+          payload: payload,
+          validations: {
+            otp: {type: :string, required: true},
+            reference: {type: :reference, required: true}
+          }
+        )
+
+        response = @connection.post("/charge/submit_otp", payload)
+        handle_response(response)
+      end
+
+      private
+
+      def validate_mobile_money_payload!(payload)
+        validate_fields!(
+          payload: payload,
+          validations: {
+            email: {type: :email, required: true},
+            amount: {type: :positive_integer, required: true},
+            currency: {type: :currency, required: false},
+            reference: {type: :reference, required: false},
+            callback_url: {required: false},
+            metadata: {required: false},
+            mobile_money: {required: true}
+          }
+        )
+
+        mobile_money = payload[:mobile_money] || payload["mobile_money"]
+        validate_hash!(input: mobile_money, name: "mobile_money")
+
+        phone = mobile_money[:phone] || mobile_money["phone"]
+        validate_presence!(value: phone, name: "mobile_money phone")
+
+        provider = mobile_money[:provider] || mobile_money["provider"]
+        validate_mobile_money_provider!(provider)
+      end
+
+      def validate_mobile_money_provider!(provider)
+        normalized = provider&.to_s&.downcase
+        validate_allowed_values!(
+          value: normalized,
+          allowed_values: MOBILE_MONEY_PROVIDERS,
+          name: "mobile_money provider",
+          allow_nil: false
+        )
+      end
+
+      def normalize_mobile_money_provider(payload)
+        mm = payload[:mobile_money] || payload["mobile_money"] || {}
+        provider = mm[:provider] || mm["provider"]
+        normalized_provider = provider&.to_s&.downcase
+        # Avoid mutating the caller's payload
+        payload.merge(mobile_money: mm.merge(provider: normalized_provider))
+      end
+    end
+  end
+end
diff --git a/lib/paystack_sdk/resources/customers.rb b/lib/paystack_sdk/resources/customers.rb
index 9fecdb9..c112fa4 100644
--- a/lib/paystack_sdk/resources/customers.rb
+++ b/lib/paystack_sdk/resources/customers.rb
@@ -68,13 +68,9 @@ def list(per_page: 50, page: 1, **params)
         validate_positive_integer!(value: per_page, name: "per_page", allow_nil: true)
         validate_positive_integer!(value: page, name: "page", allow_nil: true)
 
-        if params[:from]
-          validate_date_format!(date_str: params[:from], name: "from")
-        end
+        validate_date_format!(date_str: params[:from], name: "from") if params[:from]
 
-        if params[:to]
-          validate_date_format!(date_str: params[:to], name: "to")
-        end
+        validate_date_format!(date_str: params[:to], name: "to") if params[:to]
 
         query_params = {perPage: per_page, page: page}.merge(params)
         response = @connection.get("customer", query_params)
diff --git a/lib/paystack_sdk/response.rb b/lib/paystack_sdk/response.rb
index 87fdba8..9aaf979 100644
--- a/lib/paystack_sdk/response.rb
+++ b/lib/paystack_sdk/response.rb
@@ -85,9 +85,7 @@ def initialize(response)
           @error_message = @api_message || "Client error"
 
           # Still raise for authentication issues as these are usually config problems
-          if @status_code == 401
-            raise AuthenticationError.new(@api_message || "Authentication failed")
-          end
+          raise AuthenticationError.new(@api_message || "Authentication failed") if @status_code == 401
         when 429
           # Rate limiting - raise as users need to implement retry logic
           retry_after = response.headers["Retry-After"]
@@ -211,7 +209,7 @@ def key?(key)
     # @yield [key, value] For hashes, passes each key-value pair
     # @yield [value] For arrays, passes each item
     # @return [Response, Enumerator] Self for chaining or Enumerator if no block given
-    def each(&block)
+    def each
       return enum_for(:each) unless block_given?
 
       if @raw_data.is_a?(Hash)
@@ -231,7 +229,7 @@ def each(&block)
     #   @return [Integer] The number of items
     # @!method empty?
     #   @return [Boolean] Whether the collection is empty
-    [:size, :length, :count, :empty?].each do |method_name|
+    %i[size length count empty?].each do |method_name|
       define_method(method_name) do
         @raw_data.send(method_name) if @raw_data.respond_to?(method_name)
       end
@@ -242,9 +240,10 @@ def each(&block)
     #   @return [Object, Response] The first item, wrapped if necessary
     # @!method last
     #   @return [Object, Response] The last item, wrapped if necessary
-    [:first, :last].each do |method_name|
+    %i[first last].each do |method_name|
       define_method(method_name) do
         return nil unless @raw_data.is_a?(Array)
+
         wrap_value(@raw_data.send(method_name))
       end
     end
@@ -261,9 +260,7 @@ def extract_identifier(body)
 
       # First try to get identifier from the message
       message = body["message"].to_s.downcase
-      if message =~ /with (id|code|reference|email): ([^\s]+)/i
-        return $2
-      end
+      return ::Regexp.last_match(2) if message =~ /with (id|code|reference|email): ([^\s]+)/i
 
       # If not found in message, try to extract from error code
       if body["code"]&.match?(/^(transaction|customer)_/)
@@ -288,6 +285,7 @@ def extract_api_message(body)
     # @return [Hash, Array, nil] The data from the response
     def extract_data_from_body(body)
       return body unless body.is_a?(Hash)
+
       body["data"] || body
     end
 
diff --git a/lib/paystack_sdk/validations.rb b/lib/paystack_sdk/validations.rb
index 9a1276d..d6a3bbc 100644
--- a/lib/paystack_sdk/validations.rb
+++ b/lib/paystack_sdk/validations.rb
@@ -37,9 +37,9 @@ module Validations
     # @param name [String] Name of the parameter for error messages
     # @raise [PaystackSdk::InvalidFormatError] If input is not a hash
     def validate_hash!(input:, name: "Payload")
-      unless input.is_a?(Hash)
-        raise PaystackSdk::InvalidFormatError.new(name, "Hash")
-      end
+      return if input.is_a?(Hash)
+
+      raise PaystackSdk::InvalidFormatError.new(name, "Hash")
     end
 
     # Validates that required parameters are present in a payload.
@@ -53,10 +53,10 @@ def validate_required_params!(payload:, required_params:, operation_name: "Opera
         !payload.key?(param) && !payload.key?(param.to_s)
       end
 
-      unless missing_params.empty?
-        param = missing_params.first
-        raise PaystackSdk::MissingParamError.new(param)
-      end
+      return if missing_params.empty?
+
+      param = missing_params.first
+      raise PaystackSdk::MissingParamError.new(param)
     end
 
     # Validates that a value is present (not nil or empty).
@@ -91,9 +91,9 @@ def validate_positive_integer!(value:, name: "Parameter", allow_nil: true)
     # @param name [String] Name of the parameter for error messages
     # @raise [PaystackSdk::InvalidFormatError] If reference format is invalid
     def validate_reference_format!(reference:, name: "Reference")
-      unless reference.to_s.match?(/^[a-zA-Z0-9._=-]+$/)
-        raise PaystackSdk::InvalidFormatError.new(name, "alphanumeric characters and the following: -, ., =")
-      end
+      return if reference.to_s.match?(/^[a-zA-Z0-9._=-]+$/)
+
+      raise PaystackSdk::InvalidFormatError.new(name, "alphanumeric characters and the following: -, ., =")
     end
 
     # Validates a date string format.
@@ -106,6 +106,7 @@ def validate_reference_format!(reference:, name: "Reference")
     def validate_date_format!(date_str:, name: "Date", allow_nil: true)
       if date_str.nil?
         raise PaystackSdk::MissingParamError.new(name) unless allow_nil
+
         return
       end
 
@@ -136,13 +137,14 @@ def validate_date_format!(date_str:, name: "Date", allow_nil: true)
     def validate_allowed_values!(value:, allowed_values:, name: "Parameter", allow_nil: true)
       if value.nil?
         raise PaystackSdk::MissingParamError.new(name) unless allow_nil
+
         return
       end
 
-      unless allowed_values.include?(value)
-        allowed_list = allowed_values.join(", ")
-        raise PaystackSdk::InvalidValueError.new(name, "must be one of: #{allowed_list}")
-      end
+      return if allowed_values.include?(value)
+
+      allowed_list = allowed_values.join(", ")
+      raise PaystackSdk::InvalidValueError.new(name, "must be one of: #{allowed_list}")
     end
 
     # Validates an email format.
@@ -154,12 +156,13 @@ def validate_allowed_values!(value:, allowed_values:, name: "Parameter", allow_n
     def validate_email!(email:, name: "Email", allow_nil: false)
       if email.nil?
         raise PaystackSdk::MissingParamError.new(name) unless allow_nil
+
         return
       end
 
-      unless email.to_s.match?(/\A[^@\s]+@[^@\s]+\.[^@\s]+\z/)
-        raise PaystackSdk::InvalidFormatError.new(name, "valid email address")
-      end
+      return if email.to_s.match?(/\A[^@\s]+@[^@\s]+\.[^@\s]+\z/)
+
+      raise PaystackSdk::InvalidFormatError.new(name, "valid email address")
     end
 
     # Validates a currency code format.
@@ -171,12 +174,13 @@ def validate_email!(email:, name: "Email", allow_nil: false)
     def validate_currency!(currency:, name: "Currency", allow_nil: true)
       if currency.nil?
         raise PaystackSdk::MissingParamError.new(name) unless allow_nil
+
         return
       end
 
-      unless currency.to_s.match?(/\A[A-Z]{3}\z/)
-        raise PaystackSdk::InvalidFormatError.new(name, "3-letter ISO code (e.g., NGN, USD, GHS)")
-      end
+      return if currency.to_s.match?(/\A[A-Z]{3}\z/)
+
+      raise PaystackSdk::InvalidFormatError.new(name, "3-letter ISO code (e.g., NGN, USD, GHS)")
     end
 
     # Validates multiple fields at once.
diff --git a/paystack_sdk.gemspec b/paystack_sdk.gemspec
index dbee9af..9a4d08e 100644
--- a/paystack_sdk.gemspec
+++ b/paystack_sdk.gemspec
@@ -39,11 +39,11 @@ Gem::Specification.new do |spec|
 
   # Dependencies
   spec.add_dependency "faraday", "~> 2.13.1"
-  spec.add_development_dependency "rspec", "~> 3.13"
-  spec.add_development_dependency "standard", "~> 1.49.0"
+  spec.add_development_dependency "debug", "~> 1.9.0"
   spec.add_development_dependency "irb", "~> 1.15.1"
   spec.add_development_dependency "rake", "~> 13.2.1"
-  spec.add_development_dependency "debug", "~> 1.9.0"
+  spec.add_development_dependency "rspec", "~> 3.13"
+  spec.add_development_dependency "standard", "~> 1.49.0"
 
   # For more information and examples about making a new gem, check out our
   # guide at: https://bundler.io/guides/creating_gem.html
diff --git a/spec/client_spec.rb b/spec/client_spec.rb
index 5396297..3eb97d8 100644
--- a/spec/client_spec.rb
+++ b/spec/client_spec.rb
@@ -41,4 +41,13 @@
       expect(client.transactions).to eq(transactions_double)
     end
   end
+
+  describe "#charges" do
+    it "returns an instance of Charges resource" do
+      charges_double = instance_double(PaystackSdk::Resources::Charges)
+      allow(PaystackSdk::Resources::Charges).to receive(:new).and_return(charges_double)
+
+      expect(client.charges).to eq(charges_double)
+    end
+  end
 end
diff --git a/spec/resources/banks_spec.rb b/spec/resources/banks_spec.rb
index d5b9a33..73a9ba7 100644
--- a/spec/resources/banks_spec.rb
+++ b/spec/resources/banks_spec.rb
@@ -24,9 +24,9 @@
     end
 
     it "raises error for invalid currency" do
-      expect {
+      expect do
         banks.list(currency: "INVALID")
-      }.to raise_error(PaystackSdk::InvalidValueError, /currency/)
+      end.to raise_error(PaystackSdk::InvalidValueError, /currency/)
     end
   end
 end
diff --git a/spec/resources/charges_spec.rb b/spec/resources/charges_spec.rb
new file mode 100644
index 0000000..23b6959
--- /dev/null
+++ b/spec/resources/charges_spec.rb
@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+RSpec.describe PaystackSdk::Resources::Charges do
+  let(:connection) { instance_double("PaystackSdk::Connection") }
+  let(:charges) { described_class.new(connection) }
+
+  describe "#mobile_money" do
+    let(:payload) do
+      {
+        email: "customer@email.com",
+        amount: 10_000,
+        currency: "GHS",
+        mobile_money: {
+          phone: "0551234987",
+          provider: "mtn"
+        }
+      }
+    end
+
+    it "creates a mobile money charge" do
+      response_double = double("Response", success?: true, status: "pay_offline")
+      expect(connection).to receive(:post)
+        .with("/charge", payload)
+        .and_return(response_double)
+      expect(PaystackSdk::Response).to receive(:new).with(response_double)
+        .and_return(response_double)
+
+      response = charges.mobile_money(payload)
+
+      expect(response.success?).to be true
+      expect(response.status).to eq("pay_offline")
+    end
+
+    it "accepts provider codes in different cases and normalizes before POST" do
+      payload[:mobile_money][:provider] = "MTN"
+      normalized_payload = payload.merge(
+        mobile_money: payload[:mobile_money].merge(provider: "mtn")
+      )
+      response_double = double("Response", success?: true)
+      expect(connection).to receive(:post)
+        .with("/charge", normalized_payload)
+        .and_return(response_double)
+      expect(PaystackSdk::Response).to receive(:new).with(response_double)
+        .and_return(response_double)
+
+      expect { charges.mobile_money(payload) }.not_to raise_error
+    end
+
+    it "raises an error when mobile_money provider is invalid" do
+      payload[:mobile_money][:provider] = "invalid"
+
+      expect { charges.mobile_money(payload) }
+        .to raise_error(PaystackSdk::InvalidValueError, /mobile_money provider/)
+    end
+
+    it "raises an error when required mobile_money details are missing" do
+      payload[:mobile_money].delete(:phone)
+
+      expect { charges.mobile_money(payload) }
+        .to raise_error(PaystackSdk::MissingParamError, /mobile_money phone/)
+    end
+  end
+
+  describe "#submit_otp" do
+    let(:otp_payload) { {otp: "123456", reference: "r13havfcdt7btcm"} }
+
+    it "submits the otp for a charge" do
+      response_double = double("Response", success?: true, status: "success")
+      expect(connection).to receive(:post)
+        .with("/charge/submit_otp", otp_payload)
+        .and_return(response_double)
+      expect(PaystackSdk::Response).to receive(:new).with(response_double)
+        .and_return(response_double)
+
+      response = charges.submit_otp(otp_payload)
+      expect(response.status).to eq("success")
+    end
+
+    it "raises an error when otp is missing" do
+      otp_payload.delete(:otp)
+
+      expect { charges.submit_otp(otp_payload) }
+        .to raise_error(PaystackSdk::MissingParamError, /otp/)
+    end
+  end
+end
diff --git a/spec/resources/transactions_spec.rb b/spec/resources/transactions_spec.rb
index 36cfed4..3d8796e 100644
--- a/spec/resources/transactions_spec.rb
+++ b/spec/resources/transactions_spec.rb
@@ -8,7 +8,7 @@
     let(:params) do
       {
         email: "customer@email.com",
-        amount: 10000,
+        amount: 10_000,
         currency: "GHS"
       }
     end
@@ -133,14 +133,14 @@
       {
         authorization_code: "AUTH_72btv547",
         email: "customer@email.com",
-        amount: 10000
+        amount: 10_000
       }
     end
 
     context "with successful response" do
       it "charges the authorization" do
         response_double = double("Response", success?: true, status: "success",
-          api_message: "Charge attempted", amount: 35247, reference: "0m7frfnr47ezyxl",
+          api_message: "Charge attempted", amount: 35_247, reference: "0m7frfnr47ezyxl",
           authorization: double("Authorization", authorization_code: "AUTH_uh8bcl3zbn"),
           customer: double("Customer", email: "customer@email.com"))
         expect(connection).to receive(:post)
@@ -154,7 +154,7 @@
         expect(response.success?).to be true
         expect(response.status).to be "success"
         expect(response.api_message).to eq("Charge attempted")
-        expect(response.amount).to eq(35247)
+        expect(response.amount).to eq(35_247)
         expect(response.reference).to eq("0m7frfnr47ezyxl")
         expect(response.authorization.authorization_code).to eq("AUTH_uh8bcl3zbn")
         expect(response.customer.email).to eq("customer@email.com")
@@ -193,7 +193,7 @@
       {
         authorization_code: "AUTH_72btv547",
         currency: "NGN",
-        amount: 10000,
+        amount: 10_000,
         email: "customer@email.com"
       }
     end
diff --git a/spec/resources/transfer_recipients_spec.rb b/spec/resources/transfer_recipients_spec.rb
index 07cf38f..cad0396 100644
--- a/spec/resources/transfer_recipients_spec.rb
+++ b/spec/resources/transfer_recipients_spec.rb
@@ -22,9 +22,9 @@
     end
 
     it "raises error for missing required params" do
-      expect {
+      expect do
         recipients.create({})
-      }.to raise_error(PaystackSdk::MissingParamError)
+      end.to raise_error(PaystackSdk::MissingParamError)
     end
   end
 
diff --git a/spec/resources/transfers_spec.rb b/spec/resources/transfers_spec.rb
index 6b5713e..1bbcfe3 100644
--- a/spec/resources/transfers_spec.rb
+++ b/spec/resources/transfers_spec.rb
@@ -6,7 +6,7 @@
   let(:params) do
     {
       source: "balance",
-      amount: 50000,
+      amount: 50_000,
       recipient: "RCP_1234567890",
       reason: "Test transfer"
     }
@@ -23,9 +23,9 @@
     end
 
     it "raises error for missing required params" do
-      expect {
+      expect do
         transfers.create({})
-      }.to raise_error(PaystackSdk::MissingParamError)
+      end.to raise_error(PaystackSdk::MissingParamError)
     end
   end
 
diff --git a/spec/resources/verification_spec.rb b/spec/resources/verification_spec.rb
index 6c76a04..2e728c6 100644
--- a/spec/resources/verification_spec.rb
+++ b/spec/resources/verification_spec.rb
@@ -15,15 +15,15 @@
     end
 
     it "raises error for missing account_number" do
-      expect {
+      expect do
         verification.resolve_account(account_number: nil, bank_code: "058")
-      }.to raise_error(PaystackSdk::MissingParamError, /account_number/)
+      end.to raise_error(PaystackSdk::MissingParamError, /account_number/)
     end
 
     it "raises error for missing bank_code" do
-      expect {
+      expect do
         verification.resolve_account(account_number: "0001234567", bank_code: nil)
-      }.to raise_error(PaystackSdk::MissingParamError, /bank_code/)
+      end.to raise_error(PaystackSdk::MissingParamError, /bank_code/)
     end
   end
 
@@ -38,9 +38,9 @@
     end
 
     it "raises error for missing bin" do
-      expect {
+      expect do
         verification.resolve_card_bin(nil)
-      }.to raise_error(PaystackSdk::MissingParamError, /bin/)
+      end.to raise_error(PaystackSdk::MissingParamError, /bin/)
     end
   end
 
@@ -69,9 +69,9 @@
       %i[account_number account_name account_type bank_code country_code document_type].each do |field|
         params = required_params.dup
         params.delete(field)
-        expect {
+        expect do
           verification.validate_account(params)
-        }.to raise_error(PaystackSdk::MissingParamError, /#{field}/)
+        end.to raise_error(PaystackSdk::MissingParamError, /#{field}/)
       end
     end