diff --git a/packages/modules/tax/integration-tests/__tests__/index.spec.ts b/packages/modules/tax/integration-tests/__tests__/index.spec.ts
index 1534dc6bc5..a10ddd5c86 100644
--- a/packages/modules/tax/integration-tests/__tests__/index.spec.ts
+++ b/packages/modules/tax/integration-tests/__tests__/index.spec.ts
@@ -1,8 +1,8 @@
-import { moduleIntegrationTestRunner } from "medusa-test-utils"
 import { ITaxModuleService } from "@medusajs/types"
-import { setupTaxStructure } from "../utils/setup-tax-structure"
 import { Module, Modules } from "@medusajs/utils"
 import { TaxModuleService } from "@services"
+import { moduleIntegrationTestRunner } from "medusa-test-utils"
+import { setupTaxStructure } from "../utils/setup-tax-structure"
 
 jest.setTimeout(30000)
 
@@ -62,6 +62,191 @@ moduleIntegrationTestRunner<ITaxModuleService>({
         })
       })
 
+      it("should create tax region", async () => {
+        const region = await service.createTaxRegions({
+          country_code: "US",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        })
+
+        expect(region).toEqual(
+          expect.objectContaining({
+            id: region.id,
+            country_code: "us",
+          })
+        )
+      })
+
+      it("should create two tax regions with the same country code but different province", async () => {
+        const regionOne = await service.createTaxRegions({
+          country_code: "US",
+          province_code: "CA",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        })
+
+        const regionTwo = await service.createTaxRegions({
+          country_code: "US",
+          province_code: "NY",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        })
+
+        expect(regionOne).toEqual(
+          expect.objectContaining({
+            id: regionOne.id,
+            country_code: "us",
+            province_code: "ca",
+          })
+        )
+
+        expect(regionTwo).toEqual(
+          expect.objectContaining({
+            id: regionTwo.id,
+            country_code: "us",
+            province_code: "ny",
+          })
+        )
+      })
+
+      it("should create two tax regions in a child-parent-like relationship", async () => {
+        const regionOne = await service.createTaxRegions({
+          country_code: "US",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        })
+
+        const regionTwo = await service.createTaxRegions({
+          country_code: "US",
+          parent_id: regionOne.id,
+          province_code: "NY",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        })
+
+        expect(regionOne).toEqual(
+          expect.objectContaining({
+            id: regionOne.id,
+            country_code: "us",
+            province_code: null,
+          })
+        )
+
+        expect(regionTwo).toEqual(
+          expect.objectContaining({
+            id: regionTwo.id,
+            country_code: "us",
+            province_code: "ny",
+          })
+        )
+      })
+
+      it("should create three tax regions in a child-parent-like relationship", async () => {
+        const regionOne = await service.createTaxRegions({
+          country_code: "US",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        })
+
+        const regionTwo = await service.createTaxRegions({
+          country_code: "US",
+          parent_id: regionOne.id,
+          province_code: "NY",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        })
+
+        const regionThree = await service.createTaxRegions({
+          country_code: "US",
+          parent_id: regionOne.id,
+          province_code: "NE",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        })
+
+        expect(regionOne).toEqual(
+          expect.objectContaining({
+            id: regionOne.id,
+            country_code: "us",
+            province_code: null,
+          })
+        )
+
+        expect(regionTwo).toEqual(
+          expect.objectContaining({
+            id: regionTwo.id,
+            country_code: "us",
+            province_code: "ny",
+          })
+        )
+
+        expect(regionThree).toEqual(
+          expect.objectContaining({
+            id: regionThree.id,
+            country_code: "us",
+            province_code: "ne",
+          })
+        )
+      })
+
+      it("should throw when creating a tax region with a country code of an existing region", async () => {
+        await service.createTaxRegions({
+          country_code: "US",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        })
+
+        const error = await service.createTaxRegions({
+          country_code: "US",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        }).catch(e => e)
+
+        expect(error.message).toEqual("Tax region with country_code: us, already exists.")
+      })
+
+      it("should throw when creating a tax region with a country code and province code of an existing region", async () => {
+        await service.createTaxRegions({
+          country_code: "US",
+          province_code: "CA",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        })
+
+        const error = await service.createTaxRegions({
+          country_code: "US",
+          province_code: "CA",
+          default_tax_rate: {
+            name: "Test Rate",
+            rate: 0.2,
+          },
+        }).catch(e => e)
+
+        expect(error.message).toEqual("Tax region with country_code: us, province_code: ca, already exists.")
+      })
+      
       it("should create tax rates and update them", async () => {
         const region = await service.createTaxRegions({
           country_code: "US",
diff --git a/packages/modules/tax/src/migrations/.snapshot-medusa-tax.json b/packages/modules/tax/src/migrations/.snapshot-medusa-tax.json
index 5c37511474..b367b1a332 100644
--- a/packages/modules/tax/src/migrations/.snapshot-medusa-tax.json
+++ b/packages/modules/tax/src/migrations/.snapshot-medusa-tax.json
@@ -168,7 +168,15 @@
           "composite": false,
           "primary": false,
           "unique": false,
-          "expression": "CREATE UNIQUE INDEX IF NOT EXISTS \"IDX_tax_region_unique_country_province\" ON \"tax_region\" (country_code, province_code)"
+          "expression": "CREATE UNIQUE INDEX IF NOT EXISTS \"IDX_tax_region_unique_country_province\" ON \"tax_region\" (country_code, province_code) WHERE deleted_at IS NULL"
+        },
+        {
+          "keyName": "IDX_tax_region_unique_country_nullable_province",
+          "columnNames": [],
+          "composite": false,
+          "primary": false,
+          "unique": false,
+          "expression": "CREATE UNIQUE INDEX IF NOT EXISTS \"IDX_tax_region_unique_country_nullable_province\" ON \"tax_region\" (country_code) WHERE province_code IS NULL AND deleted_at IS NULL"
         },
         {
           "keyName": "tax_region_pkey",
diff --git a/packages/modules/tax/src/migrations/Migration20240710135844.ts b/packages/modules/tax/src/migrations/Migration20240710135844.ts
new file mode 100644
index 0000000000..dc889699e7
--- /dev/null
+++ b/packages/modules/tax/src/migrations/Migration20240710135844.ts
@@ -0,0 +1,17 @@
+import { Migration } from '@mikro-orm/migrations';
+
+export class Migration20240710135844 extends Migration {
+
+  async up(): Promise<void> {
+    this.addSql('drop index if exists "IDX_tax_region_unique_country_province";');
+    this.addSql('CREATE UNIQUE INDEX IF NOT EXISTS "IDX_tax_region_unique_country_province" ON "tax_region" (country_code, province_code) WHERE deleted_at IS NULL;');
+    this.addSql('CREATE UNIQUE INDEX IF NOT EXISTS "IDX_tax_region_unique_country_nullable_province" ON "tax_region" (country_code) WHERE province_code IS NULL AND deleted_at IS NULL;');
+  }
+
+  async down(): Promise<void> {
+    this.addSql('drop index if exists "IDX_tax_region_unique_country_province";');
+    this.addSql('drop index if exists "IDX_tax_region_unique_country_nullable_province";');
+    this.addSql('CREATE UNIQUE INDEX IF NOT EXISTS "IDX_tax_region_unique_country_province" ON "tax_region" (country_code, province_code);');
+  }
+
+}
diff --git a/packages/modules/tax/src/models/tax-region.ts b/packages/modules/tax/src/models/tax-region.ts
index 82580a07e5..e37f824c73 100644
--- a/packages/modules/tax/src/models/tax-region.ts
+++ b/packages/modules/tax/src/models/tax-region.ts
@@ -27,6 +27,8 @@ type OptionalTaxRegionProps = DAL.SoftDeletableModelDateColumns
 
 const TABLE_NAME = "tax_region"
 
+export const countryCodeNullProvinceIndexName =
+  "IDX_tax_region_unique_country_nullable_province"
 export const countryCodeProvinceIndexName =
   "IDX_tax_region_unique_country_province"
 const countryCodeProvinceIndexStatement = createPsqlIndexStatementHelper({
@@ -34,8 +36,18 @@ const countryCodeProvinceIndexStatement = createPsqlIndexStatementHelper({
   tableName: TABLE_NAME,
   columns: ["country_code", "province_code"],
   unique: true,
+  where: "deleted_at IS NULL",
 })
 
+const countryCodeNullableProvinceIndexStatement =
+  createPsqlIndexStatementHelper({
+    name: countryCodeNullProvinceIndexName,
+    tableName: TABLE_NAME,
+    columns: ["country_code"],
+    unique: true,
+    where: "province_code IS NULL AND deleted_at IS NULL",
+  })
+
 export const taxRegionProviderTopLevelCheckName =
   "CK_tax_region_provider_top_level"
 export const taxRegionCountryTopLevelCheckName =
@@ -49,6 +61,7 @@ export const taxRegionCountryTopLevelCheckName =
   name: taxRegionCountryTopLevelCheckName,
   expression: `parent_id IS NULL OR province_code IS NOT NULL`,
 })
+@countryCodeNullableProvinceIndexStatement.MikroORMIndex()
 @countryCodeProvinceIndexStatement.MikroORMIndex()
 @Entity({ tableName: TABLE_NAME })
 @Filter(DALUtils.mikroOrmSoftDeletableFilterOptions)