diff --git a/eslint-warning-thresholds.json b/eslint-warning-thresholds.json
index e777270690c..bfaeceb3350 100644
--- a/eslint-warning-thresholds.json
+++ b/eslint-warning-thresholds.json
@@ -374,12 +374,6 @@
     "@typescript-eslint/no-unsafe-enum-comparison": 4,
     "jsdoc/tag-lines": 4
   },
-  "packages/multichain/src/scope/transform.ts": {
-    "jsdoc/tag-lines": 3
-  },
-  "packages/multichain/src/scope/types.ts": {
-    "jsdoc/tag-lines": 1
-  },
   "packages/multichain/src/scope/validation.ts": {
     "jsdoc/tag-lines": 2
   },
diff --git a/packages/multichain/src/adapters/caip-permission-adapter-session-scopes.ts b/packages/multichain/src/adapters/caip-permission-adapter-session-scopes.ts
index 7e05eb01ad3..cfabd575ce7 100644
--- a/packages/multichain/src/adapters/caip-permission-adapter-session-scopes.ts
+++ b/packages/multichain/src/adapters/caip-permission-adapter-session-scopes.ts
@@ -7,7 +7,7 @@ import {
   KnownWalletNamespaceRpcMethods,
   KnownWalletRpcMethods,
 } from '../scope/constants';
-import { mergeScopes } from '../scope/transform';
+import { mergeNormalizedScopes } from '../scope/transform';
 import type {
   InternalScopesObject,
   NonWalletKnownCaipNamespace,
@@ -94,7 +94,7 @@ export const getSessionScopes = (
     'requiredScopes' | 'optionalScopes'
   >,
 ) => {
-  return mergeScopes(
+  return mergeNormalizedScopes(
     getNormalizedScopesObject(caip25CaveatValue.requiredScopes),
     getNormalizedScopesObject(caip25CaveatValue.optionalScopes),
   );
diff --git a/packages/multichain/src/caip25Permission.test.ts b/packages/multichain/src/caip25Permission.test.ts
index 4ae70e7c018..a52127b901a 100644
--- a/packages/multichain/src/caip25Permission.test.ts
+++ b/packages/multichain/src/caip25Permission.test.ts
@@ -475,7 +475,7 @@ describe('caip25EndowmentBuilder', () => {
 describe('caip25CaveatBuilder', () => {
   const findNetworkClientIdByChainId = jest.fn();
   const listAccounts = jest.fn();
-  const { validator } = caip25CaveatBuilder({
+  const { validator, merger } = caip25CaveatBuilder({
     findNetworkClientIdByChainId,
     listAccounts,
   });
@@ -698,4 +698,297 @@ describe('caip25CaveatBuilder', () => {
       }),
     ).toBeUndefined();
   });
+
+  describe('permission merger', () => {
+    describe('optionalScopes', () => {
+      it.each<{
+        description: string;
+        rightValue: Caip25CaveatValue;
+        expectedMergedValue: Caip25CaveatValue;
+        expectedDiff: Caip25CaveatValue;
+      }>([
+        {
+          description:
+            'incremental request existing scope with a new account - should return merged scope with existing chain and both accounts',
+          rightValue: {
+            optionalScopes: {
+              'eip155:1': {
+                accounts: ['eip155:1:0xbeef'],
+              },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          },
+          expectedMergedValue: {
+            optionalScopes: {
+              'eip155:1': { accounts: ['eip155:1:0xdead', 'eip155:1:0xbeef'] },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          },
+          expectedDiff: {
+            optionalScopes: {
+              'eip155:1': {
+                accounts: ['eip155:1:0xbeef'],
+              },
+            },
+            isMultichainOrigin: false,
+            requiredScopes: {},
+          },
+        },
+        {
+          description:
+            'incremental request a whole new scope without accounts - should return merged scope with previously existing chain and accounts, plus new requested chain with no accounts',
+          rightValue: {
+            optionalScopes: {
+              'eip155:10': {
+                accounts: [],
+              },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          },
+          expectedMergedValue: {
+            optionalScopes: {
+              'eip155:1': { accounts: ['eip155:1:0xdead'] },
+              'eip155:10': {
+                accounts: [],
+              },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          },
+          expectedDiff: {
+            optionalScopes: {
+              'eip155:10': {
+                accounts: [],
+              },
+            },
+            isMultichainOrigin: false,
+            requiredScopes: {},
+          },
+        },
+        {
+          description:
+            'incremental request a whole new scope with accounts - should return merged scope with previously existing chain and accounts, plus new requested chain with new account',
+          rightValue: {
+            optionalScopes: {
+              'eip155:10': {
+                accounts: ['eip155:10:0xbeef'],
+              },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          },
+          expectedMergedValue: {
+            optionalScopes: {
+              'eip155:1': { accounts: ['eip155:1:0xdead'] },
+              'eip155:10': { accounts: ['eip155:10:0xbeef'] },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          },
+          expectedDiff: {
+            optionalScopes: {
+              'eip155:10': {
+                accounts: ['eip155:10:0xbeef'],
+              },
+            },
+            isMultichainOrigin: false,
+            requiredScopes: {},
+          },
+        },
+        {
+          description:
+            'incremental request an existing scope with new accounts, and whole new scope with accounts - should return merged scope with previously existing chain and accounts, plus new requested chain with new accounts',
+          rightValue: {
+            optionalScopes: {
+              'eip155:1': {
+                accounts: ['eip155:1:0xdead', 'eip155:1:0xbeef'],
+              },
+              'eip155:10': {
+                accounts: ['eip155:10:0xdead', 'eip155:10:0xbeef'],
+              },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          },
+          expectedMergedValue: {
+            optionalScopes: {
+              'eip155:1': { accounts: ['eip155:1:0xdead', 'eip155:1:0xbeef'] },
+              'eip155:10': {
+                accounts: ['eip155:10:0xdead', 'eip155:10:0xbeef'],
+              },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          },
+          expectedDiff: {
+            optionalScopes: {
+              'eip155:1': {
+                accounts: ['eip155:1:0xbeef'],
+              },
+              'eip155:10': {
+                accounts: ['eip155:10:0xdead', 'eip155:10:0xbeef'],
+              },
+            },
+            isMultichainOrigin: false,
+            requiredScopes: {},
+          },
+        },
+        {
+          description:
+            'incremental request an existing scope with new accounts, and 2 whole new scope with accounts - should return merged scope with previously existing chain and accounts, plus new requested chains with new accounts',
+          rightValue: {
+            optionalScopes: {
+              'eip155:1': {
+                accounts: ['eip155:1:0xdead', 'eip155:1:0xbadd'],
+              },
+              'eip155:10': {
+                accounts: ['eip155:10:0xbeef', 'eip155:10:0xbadd'],
+              },
+              'eip155:426161': {
+                accounts: [
+                  'eip155:426161:0xdead',
+                  'eip155:426161:0xbeef',
+                  'eip155:426161:0xbadd',
+                ],
+              },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          },
+          expectedMergedValue: {
+            optionalScopes: {
+              'eip155:1': { accounts: ['eip155:1:0xdead', 'eip155:1:0xbadd'] },
+              'eip155:10': {
+                accounts: ['eip155:10:0xbeef', 'eip155:10:0xbadd'],
+              },
+              'eip155:426161': {
+                accounts: [
+                  'eip155:426161:0xdead',
+                  'eip155:426161:0xbeef',
+                  'eip155:426161:0xbadd',
+                ],
+              },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          },
+          expectedDiff: {
+            optionalScopes: {
+              'eip155:1': { accounts: ['eip155:1:0xbadd'] },
+              'eip155:10': {
+                accounts: ['eip155:10:0xbeef', 'eip155:10:0xbadd'],
+              },
+              'eip155:426161': {
+                accounts: [
+                  'eip155:426161:0xdead',
+                  'eip155:426161:0xbeef',
+                  'eip155:426161:0xbadd',
+                ],
+              },
+            },
+            isMultichainOrigin: false,
+            requiredScopes: {},
+          },
+        },
+      ])(
+        '$description',
+        async ({ rightValue, expectedMergedValue, expectedDiff }) => {
+          const initLeftValue: Caip25CaveatValue = {
+            optionalScopes: {
+              'eip155:1': {
+                accounts: ['eip155:1:0xdead'],
+              },
+            },
+            requiredScopes: {},
+            isMultichainOrigin: false,
+          };
+
+          const [newValue, diff] = merger(initLeftValue, rightValue);
+
+          expect(newValue).toStrictEqual(
+            expect.objectContaining(expectedMergedValue),
+          );
+          expect(diff).toStrictEqual(expect.objectContaining(expectedDiff));
+        },
+      );
+    });
+
+    describe('requiredScopes', () => {
+      it('incremental request an existing scope with new accounts, and 2 whole new scope with accounts - should return merged scope with previously existing chain and accounts, plus new requested chains with new accounts', () => {
+        const initLeftValue: Caip25CaveatValue = {
+          requiredScopes: {
+            'eip155:1': {
+              accounts: ['eip155:1:0xdead'],
+            },
+          },
+          optionalScopes: {},
+          isMultichainOrigin: false,
+        };
+
+        const rightValue: Caip25CaveatValue = {
+          requiredScopes: {
+            'eip155:1': {
+              accounts: ['eip155:1:0xdead', 'eip155:1:0xbadd'],
+            },
+            'eip155:10': {
+              accounts: ['eip155:10:0xbeef', 'eip155:10:0xbadd'],
+            },
+            'eip155:426161': {
+              accounts: [
+                'eip155:426161:0xdead',
+                'eip155:426161:0xbeef',
+                'eip155:426161:0xbadd',
+              ],
+            },
+          },
+          optionalScopes: {},
+          isMultichainOrigin: false,
+        };
+
+        const expectedMergedValue: Caip25CaveatValue = {
+          requiredScopes: {
+            'eip155:1': { accounts: ['eip155:1:0xdead', 'eip155:1:0xbadd'] },
+            'eip155:10': {
+              accounts: ['eip155:10:0xbeef', 'eip155:10:0xbadd'],
+            },
+            'eip155:426161': {
+              accounts: [
+                'eip155:426161:0xdead',
+                'eip155:426161:0xbeef',
+                'eip155:426161:0xbadd',
+              ],
+            },
+          },
+          optionalScopes: {},
+          isMultichainOrigin: false,
+        };
+        const expectedDiff: Caip25CaveatValue = {
+          requiredScopes: {
+            'eip155:1': { accounts: ['eip155:1:0xbadd'] },
+            'eip155:10': {
+              accounts: ['eip155:10:0xbeef', 'eip155:10:0xbadd'],
+            },
+            'eip155:426161': {
+              accounts: [
+                'eip155:426161:0xdead',
+                'eip155:426161:0xbeef',
+                'eip155:426161:0xbadd',
+              ],
+            },
+          },
+          optionalScopes: {},
+          isMultichainOrigin: false,
+        };
+        const [newValue, diff] = merger(initLeftValue, rightValue);
+
+        expect(newValue).toStrictEqual(
+          expect.objectContaining(expectedMergedValue),
+        );
+        expect(diff).toStrictEqual(expect.objectContaining(expectedDiff));
+      });
+    });
+  });
 });
diff --git a/packages/multichain/src/caip25Permission.ts b/packages/multichain/src/caip25Permission.ts
index 9a417f3c707..efd7880abe9 100644
--- a/packages/multichain/src/caip25Permission.ts
+++ b/packages/multichain/src/caip25Permission.ts
@@ -24,8 +24,10 @@ import { cloneDeep, isEqual } from 'lodash';
 import { getEthAccounts } from './adapters/caip-permission-adapter-eth-accounts';
 import { assertIsInternalScopesObject } from './scope/assert';
 import { isSupportedScopeString } from './scope/supported';
+import { mergeInternalScopes } from './scope/transform';
 import {
   parseScopeString,
+  type InternalScopeString,
   type ExternalScopeString,
   type InternalScopeObject,
   type InternalScopesObject,
@@ -83,7 +85,9 @@ export const caip25CaveatBuilder = ({
   findNetworkClientIdByChainId,
   listAccounts,
 }: Caip25EndowmentCaveatSpecificationBuilderOptions): EndowmentCaveatSpecificationConstraint &
-  Required<Pick<EndowmentCaveatSpecificationConstraint, 'validator'>> => {
+  Required<
+    Pick<EndowmentCaveatSpecificationConstraint, 'validator' | 'merger'>
+  > => {
   return {
     type: Caip25CaveatType,
     validator: (
@@ -150,6 +154,39 @@ export const caip25CaveatBuilder = ({
         );
       }
     },
+    merger: (
+      leftValue: Caip25CaveatValue,
+      rightValue: Caip25CaveatValue,
+    ): [Caip25CaveatValue, Caip25CaveatValue] => {
+      const mergedRequiredScopes = mergeInternalScopes(
+        leftValue.requiredScopes,
+        rightValue.requiredScopes,
+      );
+      const mergedOptionalScopes = mergeInternalScopes(
+        leftValue.optionalScopes,
+        rightValue.optionalScopes,
+      );
+
+      const mergedValue: Caip25CaveatValue = {
+        requiredScopes: mergedRequiredScopes,
+        optionalScopes: mergedOptionalScopes,
+        isMultichainOrigin: leftValue.isMultichainOrigin,
+      };
+
+      const partialDiff = diffScopesForCaip25CaveatValue(
+        leftValue,
+        mergedValue,
+        'requiredScopes',
+      );
+
+      const diff = diffScopesForCaip25CaveatValue(
+        partialDiff,
+        mergedValue,
+        'optionalScopes',
+      );
+
+      return [mergedValue, diff];
+    },
   };
 };
 
@@ -347,3 +384,49 @@ function removeScope(
     operation: CaveatMutatorOperation.RevokePermission,
   };
 }
+
+/**
+ * Returns the differential between two provided CAIP-25 permission caveat value scopes.
+ *
+ * @param originalValue - The existing CAIP-25 permission caveat value.
+ * @param mergedValue - The result from merging existing and incoming CAIP-25 permission caveat values.
+ * @param scopeToDiff - The required or optional scopes from the [CAIP-25](https://github.com/ChainAgnostic/CAIPs/blob/main/CAIPs/caip-25.md) request.
+ * @returns The differential between original and merged CAIP-25 permission caveat values.
+ */
+function diffScopesForCaip25CaveatValue(
+  originalValue: Caip25CaveatValue,
+  mergedValue: Caip25CaveatValue,
+  scopeToDiff: keyof Pick<
+    Caip25CaveatValue,
+    'optionalScopes' | 'requiredScopes'
+  >,
+): Caip25CaveatValue {
+  const diff = cloneDeep(originalValue);
+
+  for (const [scopeString, mergedScopeObject] of Object.entries(
+    mergedValue[scopeToDiff],
+  )) {
+    const internalScopeString = scopeString as InternalScopeString;
+    const originalScopeObject = diff[scopeToDiff][internalScopeString];
+
+    if (originalScopeObject) {
+      const newAccounts = mergedScopeObject.accounts.filter(
+        (account) =>
+          !diff[scopeToDiff][
+            scopeString as InternalScopeString
+          ]?.accounts.includes(account),
+      );
+      if (newAccounts.length > 0) {
+        diff[scopeToDiff][internalScopeString] = {
+          accounts: newAccounts,
+        };
+        continue;
+      }
+      delete diff[scopeToDiff][internalScopeString];
+    } else {
+      diff[scopeToDiff][internalScopeString] = mergedScopeObject;
+    }
+  }
+
+  return diff;
+}
diff --git a/packages/multichain/src/index.test.ts b/packages/multichain/src/index.test.ts
index 8465d5a24fd..4e384e43b4f 100644
--- a/packages/multichain/src/index.test.ts
+++ b/packages/multichain/src/index.test.ts
@@ -28,7 +28,8 @@ describe('@metamask/multichain', () => {
         "parseScopeString",
         "normalizeScope",
         "mergeScopeObject",
-        "mergeScopes",
+        "mergeNormalizedScopes",
+        "mergeInternalScopes",
         "normalizeAndMergeScopes",
         "caip25CaveatBuilder",
         "Caip25CaveatType",
diff --git a/packages/multichain/src/index.ts b/packages/multichain/src/index.ts
index 60732796b47..76b41aec33e 100644
--- a/packages/multichain/src/index.ts
+++ b/packages/multichain/src/index.ts
@@ -49,7 +49,8 @@ export { parseScopeString } from './scope/types';
 export {
   normalizeScope,
   mergeScopeObject,
-  mergeScopes,
+  mergeNormalizedScopes,
+  mergeInternalScopes,
   normalizeAndMergeScopes,
 } from './scope/transform';
 
diff --git a/packages/multichain/src/scope/transform.test.ts b/packages/multichain/src/scope/transform.test.ts
index b5e01b5cce9..0132920488e 100644
--- a/packages/multichain/src/scope/transform.test.ts
+++ b/packages/multichain/src/scope/transform.test.ts
@@ -1,10 +1,15 @@
 import {
   normalizeScope,
-  mergeScopes,
+  mergeNormalizedScopes,
+  mergeInternalScopes,
   mergeScopeObject,
   normalizeAndMergeScopes,
 } from './transform';
-import type { ExternalScopeObject, NormalizedScopeObject } from './types';
+import type {
+  ExternalScopeObject,
+  NormalizedScopeObject,
+  InternalScopesObject,
+} from './types';
 
 const externalScopeObject: ExternalScopeObject = {
   methods: [],
@@ -252,10 +257,120 @@ describe('Scope Transform', () => {
     });
   });
 
-  describe('mergeScopes', () => {
+  describe('mergeInternalScopes', () => {
+    it.each<{
+      description: string;
+      rightValue: InternalScopesObject;
+      expectedMergedValue: InternalScopesObject;
+    }>([
+      {
+        description:
+          'incremental request existing scope with a new account - should return merged scope with existing chain and both accounts',
+        rightValue: {
+          'eip155:1': {
+            accounts: ['eip155:1:0xbeef'],
+          },
+        },
+        expectedMergedValue: {
+          'eip155:1': { accounts: ['eip155:1:0xdead', 'eip155:1:0xbeef'] },
+        },
+      },
+      {
+        description:
+          'incremental request a whole new scope without accounts - should return merged scope with previously existing chain and accounts, plus new requested chain with no accounts',
+        rightValue: {
+          'eip155:10': {
+            accounts: [],
+          },
+        },
+        expectedMergedValue: {
+          'eip155:1': { accounts: ['eip155:1:0xdead'] },
+          'eip155:10': {
+            accounts: [],
+          },
+        },
+      },
+      {
+        description:
+          'incremental request a whole new scope with accounts - should return merged scope with previously existing chain and accounts, plus new requested chain with new account',
+        rightValue: {
+          'eip155:10': {
+            accounts: ['eip155:10:0xbeef'],
+          },
+        },
+        expectedMergedValue: {
+          'eip155:1': { accounts: ['eip155:1:0xdead'] },
+          'eip155:10': { accounts: ['eip155:10:0xbeef'] },
+        },
+      },
+      {
+        description:
+          'incremental request an existing scope with new accounts, and whole new scope with accounts - should return merged scope with previously existing chain and accounts, plus new requested chain with new accounts',
+        rightValue: {
+          'eip155:1': {
+            accounts: ['eip155:1:0xdead', 'eip155:1:0xbeef'],
+          },
+          'eip155:10': {
+            accounts: ['eip155:10:0xdead', 'eip155:10:0xbeef'],
+          },
+        },
+        expectedMergedValue: {
+          'eip155:1': { accounts: ['eip155:1:0xdead', 'eip155:1:0xbeef'] },
+          'eip155:10': {
+            accounts: ['eip155:10:0xdead', 'eip155:10:0xbeef'],
+          },
+        },
+      },
+      {
+        description:
+          'incremental request an existing scope with new accounts, and 2 whole new scope with accounts - should return merged scope with previously existing chain and accounts, plus new requested chains with new accounts',
+        rightValue: {
+          'eip155:1': {
+            accounts: ['eip155:1:0xdead', 'eip155:1:0xbadd'],
+          },
+          'eip155:10': {
+            accounts: ['eip155:10:0xbeef', 'eip155:10:0xbadd'],
+          },
+          'eip155:426161': {
+            accounts: [
+              'eip155:426161:0xdead',
+              'eip155:426161:0xbeef',
+              'eip155:426161:0xbadd',
+            ],
+          },
+        },
+        expectedMergedValue: {
+          'eip155:1': { accounts: ['eip155:1:0xdead', 'eip155:1:0xbadd'] },
+          'eip155:10': {
+            accounts: ['eip155:10:0xbeef', 'eip155:10:0xbadd'],
+          },
+          'eip155:426161': {
+            accounts: [
+              'eip155:426161:0xdead',
+              'eip155:426161:0xbeef',
+              'eip155:426161:0xbadd',
+            ],
+          },
+        },
+      },
+    ])('$description', async ({ rightValue, expectedMergedValue }) => {
+      const initLeftValue: InternalScopesObject = {
+        'eip155:1': {
+          accounts: ['eip155:1:0xdead'],
+        },
+      };
+      const mergedValue = mergeInternalScopes(initLeftValue, rightValue);
+
+      expect(mergedValue).toStrictEqual(
+        expect.objectContaining(expectedMergedValue),
+      );
+    });
+  });
+
+  describe('mergeNormalizedScopes', () => {
     it('merges the scopeObjects with matching scopeString', () => {
       expect(
-        mergeScopes(
+        mergeNormalizedScopes(
           {
             'eip155:1': {
               methods: ['a', 'b', 'c'],
@@ -282,7 +397,7 @@ describe('Scope Transform', () => {
 
     it('preserves the scopeObjects with no matching scopeString', () => {
       expect(
-        mergeScopes(
+        mergeNormalizedScopes(
           {
             'eip155:1': {
               methods: ['a', 'b', 'c'],
@@ -322,12 +437,12 @@ describe('Scope Transform', () => {
       });
     });
     it('returns an empty object when no scopes are provided', () => {
-      expect(mergeScopes({}, {})).toStrictEqual({});
+      expect(mergeNormalizedScopes({}, {})).toStrictEqual({});
     });
 
     it('returns an unchanged scope when two identical scopeObjects are provided', () => {
       expect(
-        mergeScopes(
+        mergeNormalizedScopes(
           { 'eip155:1': validScopeObject },
           { 'eip155:1': validScopeObject },
         ),
diff --git a/packages/multichain/src/scope/transform.ts b/packages/multichain/src/scope/transform.ts
index 666ff740eb5..3109b73d72a 100644
--- a/packages/multichain/src/scope/transform.ts
+++ b/packages/multichain/src/scope/transform.ts
@@ -4,6 +4,8 @@ import { cloneDeep } from 'lodash';
 import type {
   ExternalScopeObject,
   ExternalScopesObject,
+  InternalScopesObject,
+  InternalScopeString,
   NormalizedScopeObject,
   NormalizedScopesObject,
 } from './types';
@@ -59,6 +61,7 @@ export const normalizeScope = (
 
 /**
  * Merges two NormalizedScopeObjects
+ *
  * @param scopeObjectA - The first scope object to merge.
  * @param scopeObjectB - The second scope object to merge.
  * @returns The merged scope object.
@@ -101,11 +104,12 @@ export const mergeScopeObject = (
 
 /**
  * Merges two NormalizedScopeObjects
- * @param scopeA - The first scope object to merge.
- * @param scopeB - The second scope object to merge.
- * @returns The merged scope object.
+ *
+ * @param scopeA - The first normalized scope object to merge.
+ * @param scopeB - The second normalized scope object to merge.
+ * @returns The merged normalized scope object from the [CAIP-25](https://github.com/ChainAgnostic/CAIPs/blob/main/CAIPs/caip-25.md) request.
  */
-export const mergeScopes = (
+export const mergeNormalizedScopes = (
   scopeA: NormalizedScopesObject,
   scopeB: NormalizedScopesObject,
 ): NormalizedScopesObject => {
@@ -134,8 +138,40 @@ export const mergeScopes = (
   return scope;
 };
 
+/**
+ * Merges two InternalScopeObjects
+ *
+ * @param scopeA - The first internal scope object to merge.
+ * @param scopeB - The second internal scope object to merge.
+ * @returns The merged internal scope object from the [CAIP-25](https://github.com/ChainAgnostic/CAIPs/blob/main/CAIPs/caip-25.md) request.
+ */
+export const mergeInternalScopes = (
+  scopeA: InternalScopesObject,
+  scopeB: InternalScopesObject,
+): InternalScopesObject => {
+  const resultScope = cloneDeep(scopeA);
+
+  Object.entries(scopeB).forEach(([scopeString, rightScopeObject]) => {
+    const internalScopeString = scopeString as InternalScopeString;
+    const leftRequiredScopeObject = resultScope[internalScopeString];
+    if (!leftRequiredScopeObject) {
+      resultScope[internalScopeString] = rightScopeObject;
+    } else {
+      resultScope[internalScopeString] = {
+        accounts: getUniqueArrayItems([
+          ...leftRequiredScopeObject.accounts,
+          ...rightScopeObject.accounts,
+        ]),
+      };
+    }
+  });
+
+  return resultScope;
+};
+
 /**
  * Normalizes and merges a set of ExternalScopesObjects into a NormalizedScopesObject (i.e. a set of NormalizedScopeObjects where references are flattened).
+ *
  * @param scopes - The external scopes to normalize and merge.
  * @returns The normalized and merged scopes.
  */
@@ -145,7 +181,7 @@ export const normalizeAndMergeScopes = (
   let mergedScopes: NormalizedScopesObject = {};
   Object.keys(scopes).forEach((scopeString) => {
     const normalizedScopes = normalizeScope(scopeString, scopes[scopeString]);
-    mergedScopes = mergeScopes(mergedScopes, normalizedScopes);
+    mergedScopes = mergeNormalizedScopes(mergedScopes, normalizedScopes);
   });
 
   return mergedScopes;
diff --git a/packages/multichain/src/scope/types.ts b/packages/multichain/src/scope/types.ts
index b13b5edae75..8993eb0cabb 100644
--- a/packages/multichain/src/scope/types.ts
+++ b/packages/multichain/src/scope/types.ts
@@ -91,6 +91,7 @@ export type ScopedProperties = Record<CaipChainId, Record<string, Json>> & {
 
 /**
  * Parses a scope string into a namespace and reference.
+ *
  * @param scopeString - The scope string to parse.
  * @returns An object containing the namespace and reference.
  */