diff --git a/docs/spec.yaml b/docs/spec.yaml
index c9931b0..a974bb8 100644
--- a/docs/spec.yaml
+++ b/docs/spec.yaml
@@ -181,6 +181,30 @@ resources:
         returns:
           type: "V60Response"
           is_array: false
+      - name: "GetRatesByPostalCode"
+        http_method: "GET"
+        path: "/request/v60/"
+        description: "Returns sales and use tax rate details from a postal code input."
+        operation_id: "getTaxRatesV60"
+        parameters:
+          - name: "postalcode"
+            type: "string"
+            required: true
+            location: "query"
+            description: "US postal code (5-digit format, e.g., 92694)"
+            validation:
+              pattern: "^[0-9]{5}$"
+              max_length: 5
+          - name: "format"
+            type: "string"
+            required: false
+            location: "query"
+            description: "Response format"
+            default: "json"
+            enum: ["json", "xml"]
+        returns:
+          type: "V60PostalCodeResponse"
+          is_array: false
       - name: "GetAccountMetrics"
         http_method: "GET"
         path: "/account/v60/metrics"
@@ -450,6 +474,250 @@ models:
         format: "float"
         required: true
         description: "Geocoded longitude"
+  - name: "V60PostalCodeResponse"
+    description: "Response for v6.0 postal code lookup - legacy format"
+    properties:
+      - name: "version"
+        type: "string"
+        required: true
+        description: "API version"
+        example: "v60"
+      - name: "rCode"
+        type: "integer"
+        format: "int64"
+        required: true
+        description: "Response code (100=success)"
+        example: 100
+      - name: "results"
+        type: "array"
+        items_type: "V60PostalCodeResult"
+        required: true
+        description: "Array of tax rate results for the postal code"
+      - name: "addressDetail"
+        type: "V60PostalCodeAddressDetail"
+        required: true
+        description: "Address details for postal code lookup"
+
+  - name: "V60PostalCodeResult"
+    description: "Individual tax rate result for a postal code"
+    properties:
+      - name: "geoPostalCode"
+        type: "string"
+        required: true
+        description: "Postal code"
+        example: "92694"
+      - name: "geoCity"
+        type: "string"
+        required: true
+        description: "City name"
+        example: "LADERA RANCH"
+      - name: "geoCounty"
+        type: "string"
+        required: true
+        description: "County name"
+        example: "ORANGE"
+      - name: "geoState"
+        type: "string"
+        required: true
+        description: "State abbreviation"
+        example: "CA"
+      - name: "taxSales"
+        type: "number"
+        format: "float"
+        required: true
+        description: "Total sales tax rate"
+        example: 0.0775
+      - name: "taxUse"
+        type: "number"
+        format: "float"
+        required: true
+        description: "Total use tax rate"
+        example: 0.0775
+      - name: "txbService"
+        type: "string"
+        required: true
+        description: "Service taxability indicator"
+        enum: ["Y", "N"]
+      - name: "txbFreight"
+        type: "string"
+        required: true
+        description: "Freight taxability indicator"
+        enum: ["Y", "N"]
+      - name: "stateSalesTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "State sales tax rate"
+        example: 0.06
+      - name: "stateUseTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "State use tax rate"
+        example: 0.06
+      - name: "citySalesTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "City sales tax rate"
+        example: 0
+      - name: "cityUseTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "City use tax rate"
+        example: 0
+      - name: "cityTaxCode"
+        type: "string"
+        required: true
+        description: "City tax code"
+        example: ""
+      - name: "countySalesTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "County sales tax rate"
+        example: 0.0025
+      - name: "countyUseTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "County use tax rate"
+        example: 0.0025
+      - name: "countyTaxCode"
+        type: "string"
+        required: true
+        description: "County tax code"
+        example: ""
+      - name: "districtSalesTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "Total district sales tax rate"
+        example: 0.015
+      - name: "districtUseTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "Total district use tax rate"
+        example: 0.015
+      - name: "district1Code"
+        type: "string"
+        required: true
+        description: "District 1 code"
+        example: "37"
+      - name: "district1SalesTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "District 1 sales tax rate"
+        example: 0
+      - name: "district1UseTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "District 1 use tax rate"
+        example: 0
+      - name: "district2Code"
+        type: "string"
+        required: true
+        description: "District 2 code"
+        example: "37"
+      - name: "district2SalesTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "District 2 sales tax rate"
+        example: 0.005
+      - name: "district2UseTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "District 2 use tax rate"
+        example: 0.005
+      - name: "district3Code"
+        type: "string"
+        required: true
+        description: "District 3 code"
+        example: ""
+      - name: "district3SalesTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "District 3 sales tax rate"
+        example: 0
+      - name: "district3UseTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "District 3 use tax rate"
+        example: 0
+      - name: "district4Code"
+        type: "string"
+        required: true
+        description: "District 4 code"
+        example: "30"
+      - name: "district4SalesTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "District 4 sales tax rate"
+        example: 0.01
+      - name: "district4UseTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "District 4 use tax rate"
+        example: 0.01
+      - name: "district5Code"
+        type: "string"
+        required: true
+        description: "District 5 code"
+        example: ""
+      - name: "district5SalesTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "District 5 sales tax rate"
+        example: 0
+      - name: "district5UseTax"
+        type: "number"
+        format: "float"
+        required: true
+        description: "District 5 use tax rate"
+        example: 0
+      - name: "originDestination"
+        type: "string"
+        required: true
+        description: "Origin/destination indicator"
+        enum: ["O", "D"]
+
+  - name: "V60PostalCodeAddressDetail"
+    description: "Address detail information for postal code lookup"
+    properties:
+      - name: "normalizedAddress"
+        type: "string"
+        required: true
+        description: "Normalized address (limited for postal code lookups)"
+        example: "feature available for geo address lookups only"
+      - name: "incorporated"
+        type: "string"
+        required: true
+        description: "Incorporation status (limited for postal code lookups)"
+        example: "feature available for geo address lookups only"
+      - name: "geoLat"
+        type: "number"
+        format: "float"
+        required: true
+        description: "Geocoded latitude (0 for postal code lookups)"
+        example: 0
+      - name: "geoLng"
+        type: "number"
+        format: "float"
+        required: true
+        description: "Geocoded longitude (0 for postal code lookups)"
+        example: 0
+
   - name: "V60AccountMetrics"
     description: "Account metrics by API key"
     properties:
@@ -855,6 +1123,95 @@ actual_api_responses:
         }
       }
 
+  v60_postal_code_lookup:
+    description: "Actual V60 response for GetRatesByPostalCode"
+    endpoint: "GET /request/v60/?postalcode=92694"
+    example: |
+      {
+        "version": "v60",
+        "rCode": 100,
+        "results": [
+          {
+            "geoPostalCode": "92694",
+            "geoCity": "LADERA RANCH",
+            "geoCounty": "ORANGE",
+            "geoState": "CA",
+            "taxSales": 0.0775,
+            "taxUse": 0.0775,
+            "txbService": "N",
+            "txbFreight": "N",
+            "stateSalesTax": 0.06,
+            "stateUseTax": 0.06,
+            "citySalesTax": 0,
+            "cityUseTax": 0,
+            "cityTaxCode": "",
+            "countySalesTax": 0.0025,
+            "countyUseTax": 0.0025,
+            "countyTaxCode": "",
+            "districtSalesTax": 0.015,
+            "districtUseTax": 0.015,
+            "district1Code": "37",
+            "district1SalesTax": 0,
+            "district1UseTax": 0,
+            "district2Code": "37",
+            "district2SalesTax": 0.005,
+            "district2UseTax": 0.005,
+            "district3Code": "",
+            "district3SalesTax": 0,
+            "district3UseTax": 0,
+            "district4Code": "30",
+            "district4SalesTax": 0.01,
+            "district4UseTax": 0.01,
+            "district5Code": "",
+            "district5SalesTax": 0,
+            "district5UseTax": 0,
+            "originDestination": "D"
+          },
+          {
+            "geoPostalCode": "92694",
+            "geoCity": "SAN JUAN CAPISTRANO",
+            "geoCounty": "ORANGE",
+            "geoState": "CA",
+            "taxSales": 0.0775,
+            "taxUse": 0.0775,
+            "txbService": "N",
+            "txbFreight": "N",
+            "stateSalesTax": 0.06,
+            "stateUseTax": 0.06,
+            "citySalesTax": 0,
+            "cityUseTax": 0,
+            "cityTaxCode": "",
+            "countySalesTax": 0.0025,
+            "countyUseTax": 0.0025,
+            "countyTaxCode": "",
+            "districtSalesTax": 0.015,
+            "districtUseTax": 0.015,
+            "district1Code": "37",
+            "district1SalesTax": 0,
+            "district1UseTax": 0,
+            "district2Code": "37",
+            "district2SalesTax": 0.005,
+            "district2UseTax": 0.005,
+            "district3Code": "",
+            "district3SalesTax": 0,
+            "district3UseTax": 0,
+            "district4Code": "30",
+            "district4SalesTax": 0.01,
+            "district4UseTax": 0.01,
+            "district5Code": "",
+            "district5SalesTax": 0,
+            "district5UseTax": 0,
+            "originDestination": "D"
+          }
+        ],
+        "addressDetail": {
+          "normalizedAddress": "feature available for geo address lookups only",
+          "incorporated": "feature available for geo address lookups only",
+          "geoLat": 0,
+          "geoLng": 0
+        }
+      }
+
   v60_account_metrics:
     description: "Actual V60AccountMetrics response"
     endpoint: "GET /account/v60/metrics"
diff --git a/examples/basic-usage.ts b/examples/basic-usage.ts
index 75c02e0..06abd5e 100644
--- a/examples/basic-usage.ts
+++ b/examples/basic-usage.ts
@@ -43,6 +43,17 @@ async function main() {
     console.log('Address:', taxByGeo.addressDetail.normalizedAddress);
     console.log('---');
 
+    // Get rates by postal code
+    const ratesByPostalCode = await client.getRatesByPostalCode({
+      postalcode: '92694',
+    });
+
+    console.log('Rates by Postal Code:');
+    console.log('Postal Code:', ratesByPostalCode.results[0]?.geoPostalCode);
+    console.log('Total Sales Tax:', ratesByPostalCode.results[0]?.taxSales);
+    console.log('Cities:', ratesByPostalCode.results.map((r) => r.geoCity).join(', '));
+    console.log('---');
+
     // Get account metrics
     const metrics = await client.getAccountMetrics();
 
diff --git a/src/client.ts b/src/client.ts
index e7f5753..e136f00 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -14,9 +14,10 @@ import {
   DEFAULT_CONFIG,
   GetSalesTaxByAddressParams,
   GetSalesTaxByGeoLocationParams,
+  GetRatesByPostalCodeParams,
   GetAccountMetricsParams,
 } from './config';
-import { V60Response, V60AccountMetrics } from './models';
+import { V60Response, V60PostalCodeResponse, V60AccountMetrics } from './models';
 
 /**
  * ZipTax API client
@@ -110,6 +111,26 @@ export class ZiptaxClient {
     });
   }
 
+  /**
+   * Get sales and use tax rate details from a postal code input
+   * @param params - Query parameters
+   * @returns V60PostalCodeResponse with tax rate details
+   */
+  async getRatesByPostalCode(params: GetRatesByPostalCodeParams): Promise<V60PostalCodeResponse> {
+    // Validate required parameters
+    validateRequired(params.postalcode, 'postalcode');
+    validateMaxLength(params.postalcode, 5, 'postalcode');
+    validatePattern(params.postalcode, /^[0-9]{5}$/, 'postalcode', '5-digit format');
+
+    // Make API request
+    return this.httpClient.get<V60PostalCodeResponse>('/request/v60/', {
+      params: {
+        postalcode: params.postalcode,
+        format: params.format || 'json',
+      },
+    });
+  }
+
   /**
    * Get account metrics related to sales and use tax
    * @param params - Query parameters (optional)
diff --git a/src/config.ts b/src/config.ts
index d2f070b..67c7f73 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -61,6 +61,16 @@ export interface GetSalesTaxByGeoLocationParams {
   format?: 'json' | 'xml';
 }
 
+/**
+ * Query parameters for GetRatesByPostalCode
+ */
+export interface GetRatesByPostalCodeParams {
+  /** US postal code (5-digit format, e.g., 92694) */
+  postalcode: string;
+  /** Response format (default: json) */
+  format?: 'json' | 'xml';
+}
+
 /**
  * Query parameters for GetAccountMetrics
  */
diff --git a/src/models/responses.ts b/src/models/responses.ts
index f5c04d6..dfd6570 100644
--- a/src/models/responses.ts
+++ b/src/models/responses.ts
@@ -139,6 +139,108 @@ export interface V60Response {
   addressDetail: V60AddressDetail;
 }
 
+/**
+ * Individual tax rate result for a postal code
+ */
+export interface V60PostalCodeResult {
+  /** Postal code */
+  geoPostalCode: string;
+  /** City name */
+  geoCity: string;
+  /** County name */
+  geoCounty: string;
+  /** State abbreviation */
+  geoState: string;
+  /** Total sales tax rate */
+  taxSales: number;
+  /** Total use tax rate */
+  taxUse: number;
+  /** Service taxability indicator */
+  txbService: 'Y' | 'N';
+  /** Freight taxability indicator */
+  txbFreight: 'Y' | 'N';
+  /** State sales tax rate */
+  stateSalesTax: number;
+  /** State use tax rate */
+  stateUseTax: number;
+  /** City sales tax rate */
+  citySalesTax: number;
+  /** City use tax rate */
+  cityUseTax: number;
+  /** City tax code */
+  cityTaxCode: string;
+  /** County sales tax rate */
+  countySalesTax: number;
+  /** County use tax rate */
+  countyUseTax: number;
+  /** County tax code */
+  countyTaxCode: string;
+  /** Total district sales tax rate */
+  districtSalesTax: number;
+  /** Total district use tax rate */
+  districtUseTax: number;
+  /** District 1 code */
+  district1Code: string;
+  /** District 1 sales tax rate */
+  district1SalesTax: number;
+  /** District 1 use tax rate */
+  district1UseTax: number;
+  /** District 2 code */
+  district2Code: string;
+  /** District 2 sales tax rate */
+  district2SalesTax: number;
+  /** District 2 use tax rate */
+  district2UseTax: number;
+  /** District 3 code */
+  district3Code: string;
+  /** District 3 sales tax rate */
+  district3SalesTax: number;
+  /** District 3 use tax rate */
+  district3UseTax: number;
+  /** District 4 code */
+  district4Code: string;
+  /** District 4 sales tax rate */
+  district4SalesTax: number;
+  /** District 4 use tax rate */
+  district4UseTax: number;
+  /** District 5 code */
+  district5Code: string;
+  /** District 5 sales tax rate */
+  district5SalesTax: number;
+  /** District 5 use tax rate */
+  district5UseTax: number;
+  /** Origin/destination indicator */
+  originDestination: 'O' | 'D';
+}
+
+/**
+ * Address detail information for postal code lookup
+ */
+export interface V60PostalCodeAddressDetail {
+  /** Normalized address (limited for postal code lookups) */
+  normalizedAddress: string;
+  /** Incorporation status (limited for postal code lookups) */
+  incorporated: string;
+  /** Geocoded latitude (0 for postal code lookups) */
+  geoLat: number;
+  /** Geocoded longitude (0 for postal code lookups) */
+  geoLng: number;
+}
+
+/**
+ * Response for v6.0 postal code lookup - legacy format
+ */
+export interface V60PostalCodeResponse {
+  /** API version */
+  version: string;
+  /** Response code (100=success) */
+  rCode: number;
+  /** Array of tax rate results for the postal code */
+  results: V60PostalCodeResult[];
+  /** Address details for postal code lookup */
+  addressDetail: V60PostalCodeAddressDetail;
+}
+
 /**
  * Account metrics by API key
  */
diff --git a/tests/client.test.ts b/tests/client.test.ts
index 22c2667..03e92e8 100644
--- a/tests/client.test.ts
+++ b/tests/client.test.ts
@@ -64,6 +64,55 @@ const mockV60Response = {
   },
 };
 
+const mockPostalCodeResponse = {
+  version: 'v60',
+  rCode: 100,
+  results: [
+    {
+      geoPostalCode: '92694',
+      geoCity: 'LADERA RANCH',
+      geoCounty: 'ORANGE',
+      geoState: 'CA',
+      taxSales: 0.0775,
+      taxUse: 0.0775,
+      txbService: 'N' as const,
+      txbFreight: 'N' as const,
+      stateSalesTax: 0.06,
+      stateUseTax: 0.06,
+      citySalesTax: 0,
+      cityUseTax: 0,
+      cityTaxCode: '',
+      countySalesTax: 0.0025,
+      countyUseTax: 0.0025,
+      countyTaxCode: '',
+      districtSalesTax: 0.015,
+      districtUseTax: 0.015,
+      district1Code: '37',
+      district1SalesTax: 0,
+      district1UseTax: 0,
+      district2Code: '37',
+      district2SalesTax: 0.005,
+      district2UseTax: 0.005,
+      district3Code: '',
+      district3SalesTax: 0,
+      district3UseTax: 0,
+      district4Code: '30',
+      district4SalesTax: 0.01,
+      district4UseTax: 0.01,
+      district5Code: '',
+      district5SalesTax: 0,
+      district5UseTax: 0,
+      originDestination: 'D' as const,
+    },
+  ],
+  addressDetail: {
+    normalizedAddress: 'feature available for geo address lookups only',
+    incorporated: 'feature available for geo address lookups only',
+    geoLat: 0,
+    geoLng: 0,
+  },
+};
+
 const mockAccountMetrics = {
   core_request_count: 15595,
   core_request_limit: 1000000,
@@ -211,6 +260,67 @@ describe('ZiptaxClient', () => {
     });
   });
 
+  describe('getRatesByPostalCode', () => {
+    it('should get tax rates by postal code', async () => {
+      mockHttpClient.get.mockResolvedValue(mockPostalCodeResponse);
+      const client = new ZiptaxClient({ apiKey: 'test-api-key' });
+
+      const result = await client.getRatesByPostalCode({
+        postalcode: '92694',
+      });
+
+      expect(result).toEqual(mockPostalCodeResponse);
+      expect(mockHttpClient.get).toHaveBeenCalledWith('/request/v60/', {
+        params: {
+          postalcode: '92694',
+          format: 'json',
+        },
+      });
+    });
+
+    it('should throw error for missing postal code', async () => {
+      const client = new ZiptaxClient({ apiKey: 'test-api-key' });
+      await expect(client.getRatesByPostalCode({ postalcode: '' })).rejects.toThrow(
+        ZiptaxValidationError
+      );
+    });
+
+    it('should validate postal code format (must be 5 digits)', async () => {
+      const client = new ZiptaxClient({ apiKey: 'test-api-key' });
+      await expect(client.getRatesByPostalCode({ postalcode: '1234' })).rejects.toThrow(
+        ZiptaxValidationError
+      );
+    });
+
+    it('should validate postal code format (must be numeric)', async () => {
+      const client = new ZiptaxClient({ apiKey: 'test-api-key' });
+      await expect(client.getRatesByPostalCode({ postalcode: 'ABCDE' })).rejects.toThrow(
+        ZiptaxValidationError
+      );
+    });
+
+    it('should validate postal code max length', async () => {
+      const client = new ZiptaxClient({ apiKey: 'test-api-key' });
+      await expect(client.getRatesByPostalCode({ postalcode: '123456' })).rejects.toThrow(
+        ZiptaxValidationError
+      );
+    });
+
+    it('should accept format parameter', async () => {
+      mockHttpClient.get.mockResolvedValue(mockPostalCodeResponse);
+      const client = new ZiptaxClient({ apiKey: 'test-api-key' });
+
+      await client.getRatesByPostalCode({ postalcode: '92694', format: 'xml' });
+
+      expect(mockHttpClient.get).toHaveBeenCalledWith('/request/v60/', {
+        params: {
+          postalcode: '92694',
+          format: 'xml',
+        },
+      });
+    });
+  });
+
   describe('getAccountMetrics', () => {
     it('should get account metrics', async () => {
       mockHttpClient.get.mockResolvedValue(mockAccountMetrics);