diff --git a/examples/__tests__/standard-nft/test_approval.ava.js b/examples/__tests__/standard-nft/test_approval.ava.js
index 91bb428e3..8ceaf33b5 100644
--- a/examples/__tests__/standard-nft/test_approval.ava.js
+++ b/examples/__tests__/standard-nft/test_approval.ava.js
@@ -141,7 +141,7 @@ test("Simple approve", async (t) => {
       msg: null,
     },
     {
-      attachedDeposit: "450000000000000000000",
+      attachedDeposit: "550000000000000000000",
     }
   );
   t.assert(res.result.status.SuccessValue);
@@ -165,7 +165,7 @@ test("Approve call", async (t) => {
       account_id: approvalReceiver.accountId,
       msg: "return-now",
     },
-    { attachedDeposit: "450000000000000000000", gas: "300 Tgas" }
+    { attachedDeposit: "550000000000000000000", gas: "300 Tgas" }
   );
   t.is(res, "cool");
 
diff --git a/near-contract-standards/lib/non_fungible_token/impl.js b/near-contract-standards/lib/non_fungible_token/impl.js
index c9496e120..2a6217d17 100644
--- a/near-contract-standards/lib/non_fungible_token/impl.js
+++ b/near-contract-standards/lib/non_fungible_token/impl.js
@@ -1,6 +1,6 @@
-import { UnorderedMap, LookupMap, near, UnorderedSet, assert, NearPromise, bytes, serialize } from "near-sdk-js";
+import { UnorderedMap, LookupMap, near, UnorderedSet, assert, NearPromise, bytes, serialize, } from "near-sdk-js";
 import { TokenMetadata } from "./metadata";
-import { refund_approved_account_ids, refund_deposit, refund_deposit_to_account, assert_at_least_one_yocto, bytes_for_approved_account_id, assert_one_yocto, refund_approved_account_ids_iter, } from "./utils";
+import { refund_storage_deposit, refund_deposit, refund_deposit_to_account, assert_at_least_one_yocto, assert_one_yocto, } from "./utils";
 import { NftMint, NftTransfer } from "./events";
 import { Token } from "./token";
 const GAS_FOR_RESOLVE_TRANSFER = 15000000000000n;
@@ -106,11 +106,12 @@ export class NonFungibleToken {
         const next_approval_id_by_id = expect_approval(this.next_approval_id_by_id);
         const approved_account_ids = approvals_by_id.get(token_id) ?? {};
         const approval_id = next_approval_id_by_id.get(token_id) ?? 1n;
-        const old_approval_id = approved_account_ids[account_id];
+        const old_approved_account_ids_size = serialize(approved_account_ids).length;
         approved_account_ids[account_id] = approval_id;
+        const new_approved_account_ids_size = serialize(approved_account_ids).length;
         approvals_by_id.set(token_id, approved_account_ids);
         next_approval_id_by_id.set(token_id, approval_id + 1n);
-        const storage_used = old_approval_id === null ? bytes_for_approved_account_id(account_id) : 0;
+        const storage_used = new_approved_account_ids_size - old_approved_account_ids_size;
         refund_deposit(BigInt(storage_used));
         if (msg) {
             return NearPromise.new(account_id).functionCall("nft_on_approve", bytes(serialize({ token_id, owner_id, approval_id, msg })), 0n, near.prepaidGas() - GAS_FOR_NFT_APPROVE);
@@ -127,15 +128,20 @@ export class NonFungibleToken {
         const predecessorAccountId = near.predecessorAccountId();
         assert(predecessorAccountId === owner_id, "Predecessor must be token owner.");
         const approved_account_ids = approvals_by_id.get(token_id);
+        const old_approved_account_ids_size = serialize(approved_account_ids).length;
+        let new_approved_account_ids_size;
         if (approved_account_ids[account_id]) {
             delete approved_account_ids[account_id];
-            refund_approved_account_ids_iter(predecessorAccountId, [account_id]);
             if (Object.keys(approved_account_ids).length === 0) {
                 approvals_by_id.remove(token_id);
+                new_approved_account_ids_size =
+                    serialize(approved_account_ids).length;
             }
             else {
                 approvals_by_id.set(token_id, approved_account_ids);
+                new_approved_account_ids_size = 0;
             }
+            refund_storage_deposit(predecessorAccountId, new_approved_account_ids_size - old_approved_account_ids_size);
         }
     }
     nft_revoke_all({ token_id }) {
@@ -149,7 +155,7 @@ export class NonFungibleToken {
         assert(predecessorAccountId === owner_id, "Predecessor must be token owner.");
         const approved_account_ids = approvals_by_id.get(token_id);
         if (approved_account_ids) {
-            refund_approved_account_ids(predecessorAccountId, approved_account_ids);
+            refund_storage_deposit(predecessorAccountId, serialize(approved_account_ids).length);
             approvals_by_id.remove(token_id);
         }
     }
@@ -418,7 +424,7 @@ export class NonFungibleToken {
         }
         else {
             if (approved_account_ids) {
-                refund_approved_account_ids(previous_owner_id, approved_account_ids);
+                refund_storage_deposit(previous_owner_id, serialize(approved_account_ids).length);
             }
             return true;
         }
@@ -426,7 +432,7 @@ export class NonFungibleToken {
         if (this.approvals_by_id) {
             const receiver_approvals = this.approvals_by_id.get(token_id);
             if (receiver_approvals) {
-                refund_approved_account_ids(receiver_id, receiver_approvals);
+                refund_storage_deposit(receiver_id, serialize(receiver_approvals).length);
             }
             if (approved_account_ids) {
                 this.approvals_by_id.set(token_id, approved_account_ids);
diff --git a/near-contract-standards/lib/non_fungible_token/utils.d.ts b/near-contract-standards/lib/non_fungible_token/utils.d.ts
index bd1e39720..dd2715520 100644
--- a/near-contract-standards/lib/non_fungible_token/utils.d.ts
+++ b/near-contract-standards/lib/non_fungible_token/utils.d.ts
@@ -1,9 +1,5 @@
 import { Bytes, AccountId } from "near-sdk-js";
-export declare function bytes_for_approved_account_id(account_id: AccountId): number;
-export declare function refund_approved_account_ids_iter(account_id: AccountId, approved_account_ids: AccountId[]): void;
-export declare function refund_approved_account_ids(account_id: AccountId, approved_account_ids: {
-    [approvals: AccountId]: bigint;
-}): void;
+export declare function refund_storage_deposit(account_id: AccountId, storage_released: number): void;
 export declare function refund_deposit_to_account(storage_used: bigint, account_id: AccountId): void;
 /** Assumes that the precedecessor will be refunded */
 export declare function refund_deposit(storage_used: bigint): void;
diff --git a/near-contract-standards/lib/non_fungible_token/utils.js b/near-contract-standards/lib/non_fungible_token/utils.js
index 34a89b41f..68931c013 100644
--- a/near-contract-standards/lib/non_fungible_token/utils.js
+++ b/near-contract-standards/lib/non_fungible_token/utils.js
@@ -1,19 +1,9 @@
 import { near, assert } from "near-sdk-js";
-export function bytes_for_approved_account_id(account_id) {
-    // The extra 4 bytes are coming from Borsh serialization to store the length of the string.
-    return account_id.length + 4 + 8;
-}
-export function refund_approved_account_ids_iter(account_id, approved_account_ids) {
-    const storage_released = approved_account_ids
-        .map(bytes_for_approved_account_id)
-        .reduce((a, b) => a + b);
+export function refund_storage_deposit(account_id, storage_released) {
     const promise_id = near.promiseBatchCreate(account_id);
     near.promiseBatchActionTransfer(promise_id, BigInt(storage_released) * near.storageByteCost());
     near.promiseReturn(promise_id);
 }
-export function refund_approved_account_ids(account_id, approved_account_ids) {
-    refund_approved_account_ids_iter(account_id, Array.from(Object.keys(approved_account_ids)));
-}
 export function refund_deposit_to_account(storage_used, account_id) {
     const required_cost = near.storageByteCost() * storage_used;
     const attached_deposit = near.attachedDeposit();
diff --git a/near-contract-standards/src/non_fungible_token/impl.ts b/near-contract-standards/src/non_fungible_token/impl.ts
index e79355662..86f3d7332 100644
--- a/near-contract-standards/src/non_fungible_token/impl.ts
+++ b/near-contract-standards/src/non_fungible_token/impl.ts
@@ -12,15 +12,13 @@ import {
 } from "near-sdk-js";
 import { TokenMetadata } from "./metadata";
 import {
-  refund_approved_account_ids,
+  refund_storage_deposit,
   refund_deposit,
   refund_deposit_to_account,
   assert_at_least_one_yocto,
   IntoStorageKey,
   Option,
-  bytes_for_approved_account_id,
   assert_one_yocto,
-  refund_approved_account_ids_iter,
 } from "./utils";
 import { NftMint, NftTransfer } from "./events";
 import { NonFungibleTokenResolver } from "./core/resolver";
@@ -199,15 +197,18 @@ export class NonFungibleToken
     const next_approval_id_by_id = expect_approval(this.next_approval_id_by_id);
     const approved_account_ids = approvals_by_id.get(token_id) ?? {};
     const approval_id = next_approval_id_by_id.get(token_id) ?? 1n;
-    const old_approval_id = approved_account_ids[account_id];
+    const old_approved_account_ids_size =
+      serialize(approved_account_ids).length;
     approved_account_ids[account_id] = approval_id;
+    const new_approved_account_ids_size =
+      serialize(approved_account_ids).length;
 
     approvals_by_id.set(token_id, approved_account_ids);
 
     next_approval_id_by_id.set(token_id, approval_id + 1n);
 
     const storage_used =
-      old_approval_id === null ? bytes_for_approved_account_id(account_id) : 0;
+      new_approved_account_ids_size - old_approved_account_ids_size;
     refund_deposit(BigInt(storage_used));
 
     if (msg) {
@@ -242,15 +243,23 @@ export class NonFungibleToken
     );
 
     const approved_account_ids = approvals_by_id.get(token_id);
+    const old_approved_account_ids_size =
+      serialize(approved_account_ids).length;
+    let new_approved_account_ids_size;
+
     if (approved_account_ids[account_id]) {
       delete approved_account_ids[account_id];
-      refund_approved_account_ids_iter(predecessorAccountId, [account_id]);
-
       if (Object.keys(approved_account_ids).length === 0) {
         approvals_by_id.remove(token_id);
+        new_approved_account_ids_size = serialize(approved_account_ids).length;
       } else {
         approvals_by_id.set(token_id, approved_account_ids);
+        new_approved_account_ids_size = 0;
       }
+      refund_storage_deposit(
+        predecessorAccountId,
+        new_approved_account_ids_size - old_approved_account_ids_size
+      );
     }
   }
 
@@ -270,7 +279,10 @@ export class NonFungibleToken
 
     const approved_account_ids = approvals_by_id.get(token_id);
     if (approved_account_ids) {
-      refund_approved_account_ids(predecessorAccountId, approved_account_ids);
+      refund_storage_deposit(
+        predecessorAccountId,
+        serialize(approved_account_ids).length
+      );
 
       approvals_by_id.remove(token_id);
     }
@@ -708,7 +720,10 @@ export class NonFungibleToken
       }
     } else {
       if (approved_account_ids) {
-        refund_approved_account_ids(previous_owner_id, approved_account_ids);
+        refund_storage_deposit(
+          previous_owner_id,
+          serialize(approved_account_ids).length
+        );
       }
       return true;
     }
@@ -718,7 +733,10 @@ export class NonFungibleToken
     if (this.approvals_by_id) {
       const receiver_approvals = this.approvals_by_id.get(token_id);
       if (receiver_approvals) {
-        refund_approved_account_ids(receiver_id, receiver_approvals);
+        refund_storage_deposit(
+          receiver_id,
+          serialize(receiver_approvals).length
+        );
       }
       if (approved_account_ids) {
         this.approvals_by_id.set(token_id, approved_account_ids);
diff --git a/near-contract-standards/src/non_fungible_token/utils.ts b/near-contract-standards/src/non_fungible_token/utils.ts
index 39359faa5..60d9562ad 100644
--- a/near-contract-standards/src/non_fungible_token/utils.ts
+++ b/near-contract-standards/src/non_fungible_token/utils.ts
@@ -1,17 +1,9 @@
 import { near, assert, Bytes, AccountId } from "near-sdk-js";
 
-export function bytes_for_approved_account_id(account_id: AccountId): number {
-  // The extra 4 bytes are coming from Borsh serialization to store the length of the string.
-  return account_id.length + 4 + 8;
-}
-
-export function refund_approved_account_ids_iter(
+export function refund_storage_deposit(
   account_id: AccountId,
-  approved_account_ids: AccountId[]
+  storage_released: number
 ): void {
-  const storage_released = approved_account_ids
-    .map(bytes_for_approved_account_id)
-    .reduce((a, b) => a + b);
   const promise_id = near.promiseBatchCreate(account_id);
   near.promiseBatchActionTransfer(
     promise_id,
@@ -20,16 +12,6 @@ export function refund_approved_account_ids_iter(
   near.promiseReturn(promise_id);
 }
 
-export function refund_approved_account_ids(
-  account_id: AccountId,
-  approved_account_ids: { [approvals: AccountId]: bigint }
-) {
-  refund_approved_account_ids_iter(
-    account_id,
-    Array.from(Object.keys(approved_account_ids))
-  );
-}
-
 export function refund_deposit_to_account(
   storage_used: bigint,
   account_id: AccountId