diff --git a/.eslintrc.js b/.eslintrc.js
index b5052e51d..dfc7b7e9b 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -38,6 +38,13 @@ module.exports = {
     "no-duplicate-imports": "error",
     "@typescript-eslint/no-floating-promises": ["error"],
     "@typescript-eslint/no-misused-promises": ["error", { checksVoidReturn: false }],
+    "no-restricted-imports": [
+      "error",
+      {
+        patterns: [{ group: ["@ethersproject/bignumber"], message: "Use 'src/utils/BNUtils' instead" }],
+        paths: [{ name: "ethers", importNames: ["BigNumber"], message: "Use 'src/utils/BNUtils' instead" }],
+      },
+    ],
   },
   settings: {
     node: {
diff --git a/package.json b/package.json
index 704391dc1..53d1763b6 100644
--- a/package.json
+++ b/package.json
@@ -20,6 +20,7 @@
     "@ethersproject/abi": "^5.7.0",
     "@ethersproject/abstract-provider": "^5.7.0",
     "@ethersproject/abstract-signer": "^5.7.0",
+    "@ethersproject/bignumber": "^5.7.0",
     "@google-cloud/kms": "^3.6.0",
     "@google-cloud/storage": "^6.10.1",
     "@maticnetwork/maticjs": "^3.6.0",
diff --git a/scripts/hubpool.ts b/scripts/hubpool.ts
index 3c14fe311..8d5325da5 100644
--- a/scripts/hubpool.ts
+++ b/scripts/hubpool.ts
@@ -1,14 +1,12 @@
 import minimist from "minimist";
 import { WETH9__factory as WETH9 } from "@across-protocol/contracts";
 import { constants as sdkConsts } from "@across-protocol/sdk";
-import { BigNumber, ethers, Signer } from "ethers";
+import { ethers, Signer } from "ethers";
 import { config } from "dotenv";
-import { getNetworkName, getSigner } from "../src/utils";
+import { BigNumber, bnOne, bnUint256Max, formatEther, formatUnits, getNetworkName, getSigner } from "../src/utils";
 import * as utils from "./utils";
 
 const { PROTOCOL_DEFAULT_CHAIN_ID_INDICES } = sdkConsts;
-const { MaxUint256, One: bnOne } = ethers.constants;
-const { formatEther, formatUnits } = ethers.utils;
 
 const { NODE_SUCCESS, NODE_INPUT_ERR, NODE_APP_ERR } = utils;
 
@@ -99,7 +97,7 @@ async function dispute(args: Record<string, number | string>, signer: Signer): P
 
   if (allowance.lt(bondAmount)) {
     console.log(`Approving ${network} HubPool @ ${hubPool.address} to transfer ${symbol}.`);
-    const approval = await bondToken.connect(signer).approve(hubPool.address, MaxUint256);
+    const approval = await bondToken.connect(signer).approve(hubPool.address, bnUint256Max);
     console.log(`Approval: ${approval.hash}...`);
     await approval.wait();
   }
diff --git a/src/adapter/bridges/UsdcCCTPBridge.ts b/src/adapter/bridges/UsdcCCTPBridge.ts
index 40cf0e332..c26f4e282 100644
--- a/src/adapter/bridges/UsdcCCTPBridge.ts
+++ b/src/adapter/bridges/UsdcCCTPBridge.ts
@@ -1,7 +1,7 @@
-import { BigNumber, Contract, Signer } from "ethers";
+import { Contract, Signer } from "ethers";
 import { CONTRACT_ADDRESSES, chainIdsToCctpDomains } from "../../common";
 import { BridgeTransactionDetails, BaseBridgeAdapter, BridgeEvents } from "./BaseBridgeAdapter";
-import { EventSearchConfig, Provider, TOKEN_SYMBOLS_MAP, compareAddressesSimple, assert } from "../../utils";
+import { BigNumber, EventSearchConfig, Provider, TOKEN_SYMBOLS_MAP, compareAddressesSimple, assert } from "../../utils";
 import { processEvent } from "../utils";
 import { cctpAddressToBytes32, retrieveOutstandingCCTPBridgeUSDCTransfers } from "../../utils/CCTPUtils";
 
diff --git a/src/adapter/bridges/UsdcTokenSplitterBridge.ts b/src/adapter/bridges/UsdcTokenSplitterBridge.ts
index 108e688ae..d9f98aa7d 100644
--- a/src/adapter/bridges/UsdcTokenSplitterBridge.ts
+++ b/src/adapter/bridges/UsdcTokenSplitterBridge.ts
@@ -1,8 +1,8 @@
-import { BigNumber, Signer } from "ethers";
+import { Signer } from "ethers";
 import { CONTRACT_ADDRESSES, CANONICAL_BRIDGE } from "../../common";
 import { UsdcCCTPBridge } from "./UsdcCCTPBridge";
 import { BridgeTransactionDetails, BaseBridgeAdapter, BridgeEvents } from "./BaseBridgeAdapter";
-import { EventSearchConfig, Provider, TOKEN_SYMBOLS_MAP, compareAddressesSimple, assert } from "../../utils";
+import { BigNumber, EventSearchConfig, Provider, TOKEN_SYMBOLS_MAP, compareAddressesSimple, assert } from "../../utils";
 
 export class UsdcTokenSplitterBridge extends BaseBridgeAdapter {
   protected cctpBridge: BaseBridgeAdapter;
diff --git a/src/adapter/bridges/ZKSyncBridge.ts b/src/adapter/bridges/ZKSyncBridge.ts
index 314dfb245..74204a289 100644
--- a/src/adapter/bridges/ZKSyncBridge.ts
+++ b/src/adapter/bridges/ZKSyncBridge.ts
@@ -176,7 +176,7 @@ export class ZKSyncBridge extends BaseBridgeAdapter {
     return l2Gas;
   }
 
-  protected getMailboxContract() {
+  protected getMailboxContract(): Contract {
     return this.zkSyncMailbox;
   }
 }
diff --git a/src/adapter/utils.ts b/src/adapter/utils.ts
index bd7a76cd1..11de44697 100644
--- a/src/adapter/utils.ts
+++ b/src/adapter/utils.ts
@@ -1,6 +1,7 @@
-import { BigNumber, Event } from "ethers";
+import { Event } from "ethers";
 import { TOKEN_APPROVALS_TO_FIRST_ZERO } from "../common";
 import {
+  BigNumber,
   spreadEventWithBlockNumber,
   toBN,
   MAX_SAFE_ALLOWANCE,
diff --git a/src/clients/InventoryClient.ts b/src/clients/InventoryClient.ts
index 8b83b28b6..d02f0204a 100644
--- a/src/clients/InventoryClient.ts
+++ b/src/clients/InventoryClient.ts
@@ -1,4 +1,3 @@
-import { utils as ethersUtils } from "ethers";
 import { constants, utils as sdkUtils } from "@across-protocol/sdk";
 import WETH_ABI from "../common/abi/Weth.json";
 import {
@@ -10,6 +9,7 @@ import {
   createFormatFunction,
   blockExplorerLink,
   Contract,
+  formatUnits,
   runTransaction,
   isDefined,
   DefaultLogLevels,
@@ -577,9 +577,9 @@ export class InventoryClient {
           cumulativeVirtualBalance,
           cumulativeVirtualBalanceWithShortfall,
           cumulativeVirtualBalanceWithShortfallPostRefunds,
-          targetPct: ethersUtils.formatUnits(tokenConfig.targetPct, 18),
-          targetOverage: ethersUtils.formatUnits(targetOverageBuffer, 18),
-          effectiveTargetPct: ethersUtils.formatUnits(effectiveTargetPct, 18),
+          targetPct: formatUnits(tokenConfig.targetPct, 18),
+          targetOverage: formatUnits(targetOverageBuffer, 18),
+          effectiveTargetPct: formatUnits(effectiveTargetPct, 18),
           expectedPostRelayAllocation,
           chainsToEvaluate,
         }
diff --git a/src/clients/MultiCallerClient.ts b/src/clients/MultiCallerClient.ts
index 8769b518b..42bbbe26b 100644
--- a/src/clients/MultiCallerClient.ts
+++ b/src/clients/MultiCallerClient.ts
@@ -1,7 +1,7 @@
 import { utils as sdkUtils } from "@across-protocol/sdk";
-import { BigNumber } from "ethers";
 import { DEFAULT_MULTICALL_CHUNK_SIZE, Multicall2Call } from "../common";
 import {
+  BigNumber,
   winston,
   bnZero,
   getNetworkName,
@@ -633,7 +633,8 @@ export class TryMulticallClient extends MultiCallerClient {
           mrkdwn: mrkdwn.join(""),
         };
       };
-      txnRequestsToSubmit.push(...txnCalldataToRebuild.map(rebuildTryMulticall));
+      const tryMulticallTxns = txnCalldataToRebuild.filter((txn) => txn.calldata.length !== 0).map(rebuildTryMulticall);
+      txnRequestsToSubmit.push(...tryMulticallTxns);
     }
 
     if (simulate) {
diff --git a/src/clients/bridges/op-stack/OpStackAdapter.ts b/src/clients/bridges/op-stack/OpStackAdapter.ts
index f47c07acb..0091ec93b 100644
--- a/src/clients/bridges/op-stack/OpStackAdapter.ts
+++ b/src/clients/bridges/op-stack/OpStackAdapter.ts
@@ -5,10 +5,10 @@ import {
   Contract,
   BigNumber,
   BigNumberish,
+  bnZero,
   TransactionResponse,
   Event,
   checkAddressChecksum,
-  ethers,
   spreadEventWithBlockNumber,
   assign,
   winston,
@@ -146,7 +146,7 @@ export class OpStackAdapter extends BaseAdapter {
       method,
       args,
       gasLimitMultiplier,
-      ethers.constants.Zero,
+      bnZero,
       simMode
     );
   }
diff --git a/src/clients/bridges/op-stack/UsdcCCTPBridge.ts b/src/clients/bridges/op-stack/UsdcCCTPBridge.ts
index c9144dff0..37ac2f932 100644
--- a/src/clients/bridges/op-stack/UsdcCCTPBridge.ts
+++ b/src/clients/bridges/op-stack/UsdcCCTPBridge.ts
@@ -1,7 +1,7 @@
-import { BigNumber, Contract, Signer } from "ethers";
+import { Contract, Signer } from "ethers";
 import { CONTRACT_ADDRESSES, chainIdsToCctpDomains } from "../../../common";
 import { BridgeTransactionDetails, OpStackBridge, OpStackEvents } from "./OpStackBridgeInterface";
-import { EventSearchConfig, Provider, TOKEN_SYMBOLS_MAP } from "../../../utils";
+import { BigNumber, EventSearchConfig, Provider, TOKEN_SYMBOLS_MAP } from "../../../utils";
 import { cctpAddressToBytes32, retrieveOutstandingCCTPBridgeUSDCTransfers } from "../../../utils/CCTPUtils";
 
 export class UsdcCCTPBridge extends OpStackBridge {
diff --git a/src/clients/bridges/op-stack/UsdcTokenSplitterBridge.ts b/src/clients/bridges/op-stack/UsdcTokenSplitterBridge.ts
index 887ea3560..310148178 100644
--- a/src/clients/bridges/op-stack/UsdcTokenSplitterBridge.ts
+++ b/src/clients/bridges/op-stack/UsdcTokenSplitterBridge.ts
@@ -1,7 +1,14 @@
-import { BigNumber, Signer } from "ethers";
+import { Signer } from "ethers";
 import { DefaultERC20Bridge } from "./DefaultErc20Bridge";
 import { UsdcCCTPBridge } from "./UsdcCCTPBridge";
-import { EventSearchConfig, Provider, TOKEN_SYMBOLS_MAP, assert, compareAddressesSimple } from "../../../utils";
+import {
+  BigNumber,
+  EventSearchConfig,
+  Provider,
+  TOKEN_SYMBOLS_MAP,
+  assert,
+  compareAddressesSimple,
+} from "../../../utils";
 import { BridgeTransactionDetails, OpStackBridge, OpStackEvents } from "./OpStackBridgeInterface";
 import { CONTRACT_ADDRESSES } from "../../../common";
 
diff --git a/src/clients/bridges/utils.ts b/src/clients/bridges/utils.ts
index db3c02a1d..f1ea8cb9c 100644
--- a/src/clients/bridges/utils.ts
+++ b/src/clients/bridges/utils.ts
@@ -1,6 +1,7 @@
-import { BigNumber, Contract, Event } from "ethers";
+import { Contract, Event } from "ethers";
 import { TOKEN_APPROVALS_TO_FIRST_ZERO } from "../../common";
 import {
+  BigNumber,
   MAX_SAFE_ALLOWANCE,
   blockExplorerLink,
   bnZero,
diff --git a/src/finalizer/index.ts b/src/finalizer/index.ts
index e15f5072c..4cedb298f 100644
--- a/src/finalizer/index.ts
+++ b/src/finalizer/index.ts
@@ -1,6 +1,6 @@
 import { utils as sdkUtils } from "@across-protocol/sdk";
 import assert from "assert";
-import { BigNumber, Contract, constants } from "ethers";
+import { Contract } from "ethers";
 import { getAddress } from "ethers/lib/utils";
 import { groupBy, uniq } from "lodash";
 import { AugmentedTransaction, HubPoolClient, MultiCallerClient, TransactionClient } from "../clients";
@@ -17,6 +17,8 @@ import {
 import { DataworkerConfig } from "../dataworker/DataworkerConfig";
 import { SpokePoolClientsByChain } from "../interfaces";
 import {
+  BigNumber,
+  bnZero,
   Signer,
   blockExplorerLink,
   config,
@@ -253,7 +255,7 @@ export async function finalize(
 
   const txnClient = new TransactionClient(logger);
 
-  let gasEstimation = constants.Zero;
+  let gasEstimation = bnZero;
   const batchGasLimit = BigNumber.from(10_000_000);
   // @dev To avoid running into block gas limit in case the # of finalizations gets too high, keep a running
   // counter of the approximate gas estimation and cut off the list of finalizations if it gets too high.
diff --git a/src/interfaces/InventoryManagement.ts b/src/interfaces/InventoryManagement.ts
index 4f2e76c11..37ef2899f 100644
--- a/src/interfaces/InventoryManagement.ts
+++ b/src/interfaces/InventoryManagement.ts
@@ -1,5 +1,5 @@
-import { BigNumber, utils as ethersUtils } from "ethers";
-import { TOKEN_SYMBOLS_MAP } from "../utils";
+import { utils as ethersUtils } from "ethers";
+import { BigNumber, TOKEN_SYMBOLS_MAP } from "../utils";
 
 export type TokenBalanceConfig = {
   targetOverageBuffer: BigNumber; // Max multiplier for targetPct, to give flexibility in repayment chain selection.
diff --git a/src/interfaces/Report.ts b/src/interfaces/Report.ts
index a9a81b6ff..61146b332 100644
--- a/src/interfaces/Report.ts
+++ b/src/interfaces/Report.ts
@@ -1,4 +1,4 @@
-import { BigNumber } from "ethers";
+import { BigNumber } from "../utils";
 
 export enum BundleAction {
   PROPOSED = "proposed",
diff --git a/src/interfaces/Token.ts b/src/interfaces/Token.ts
index a4b6a9354..c8acb7d53 100644
--- a/src/interfaces/Token.ts
+++ b/src/interfaces/Token.ts
@@ -1,4 +1,4 @@
-import { BigNumber } from "ethers";
+import { BigNumber } from "../utils";
 import { SortableEvent } from ".";
 
 export interface TokenTransfer extends SortableEvent {
diff --git a/src/interfaces/index.ts b/src/interfaces/index.ts
index 5d3bfc8e4..fb346ae95 100644
--- a/src/interfaces/index.ts
+++ b/src/interfaces/index.ts
@@ -1,5 +1,5 @@
-import { BigNumber } from "ethers";
 import { interfaces } from "@across-protocol/sdk";
+import { BigNumber } from "../utils";
 
 export * from "./InventoryManagement";
 export * from "./SpokePool";
diff --git a/src/monitor/Monitor.ts b/src/monitor/Monitor.ts
index 168506624..b7ca6e791 100644
--- a/src/monitor/Monitor.ts
+++ b/src/monitor/Monitor.ts
@@ -17,16 +17,17 @@ import {
   convertFromWei,
   createFormatFunction,
   ERC20,
-  ethers,
   fillStatusArray,
   blockExplorerLink,
   blockExplorerLinks,
+  formatUnits,
   getNativeTokenAddressForChain,
   getGasPrice,
   getNativeTokenSymbol,
   getNetworkName,
   getUnfilledDeposits,
   mapAsync,
+  parseUnits,
   providers,
   toBN,
   toBNWei,
@@ -42,11 +43,9 @@ import { MonitorClients, updateMonitorClients } from "./MonitorClientHelper";
 import { MonitorConfig } from "./MonitorConfig";
 import { CombinedRefunds } from "../dataworker/DataworkerUtils";
 
-export const REBALANCE_FINALIZE_GRACE_PERIOD = process.env.REBALANCE_FINALIZE_GRACE_PERIOD
-  ? Number(process.env.REBALANCE_FINALIZE_GRACE_PERIOD)
-  : 60 * 60;
 // 60 minutes, which is the length of the challenge window, so if a rebalance takes longer than this to finalize,
 // then its finalizing after the subsequent challenge period has started, which is sub-optimal.
+export const REBALANCE_FINALIZE_GRACE_PERIOD = Number(process.env.REBALANCE_FINALIZE_GRACE_PERIOD ?? 60 * 60);
 
 // bundle frequency.
 export const ALL_CHAINS_NAME = "All chains";
@@ -381,8 +380,8 @@ export class Monitor {
           token,
           account,
           currentBalance: balances[i].toString(),
-          warnThreshold: ethers.utils.parseUnits(warnThreshold.toString(), decimalValues[i]),
-          errorThreshold: ethers.utils.parseUnits(errorThreshold.toString(), decimalValues[i]),
+          warnThreshold: parseUnits(warnThreshold.toString(), decimalValues[i]),
+          errorThreshold: parseUnits(errorThreshold.toString(), decimalValues[i]),
         };
       }),
     });
@@ -397,10 +396,10 @@ export class Monitor {
             const decimals = decimalValues[i];
             let trippedThreshold: { level: "warn" | "error"; threshold: number } | null = null;
 
-            if (warnThreshold !== null && balance.lt(ethers.utils.parseUnits(warnThreshold.toString(), decimals))) {
+            if (warnThreshold !== null && balance.lt(parseUnits(warnThreshold.toString(), decimals))) {
               trippedThreshold = { level: "warn", threshold: warnThreshold };
             }
-            if (errorThreshold !== null && balance.lt(ethers.utils.parseUnits(errorThreshold.toString(), decimals))) {
+            if (errorThreshold !== null && balance.lt(parseUnits(errorThreshold.toString(), decimals))) {
               trippedThreshold = { level: "error", threshold: errorThreshold };
             }
             if (trippedThreshold !== null) {
@@ -418,7 +417,7 @@ export class Monitor {
                 text: `  ${getNetworkName(chainId)} ${symbol} balance for ${blockExplorerLink(
                   account,
                   chainId
-                )} is ${ethers.utils.formatUnits(balance, decimals)}. Threshold: ${trippedThreshold.threshold}`,
+                )} is ${formatUnits(balance, decimals)}. Threshold: ${trippedThreshold.threshold}`,
               };
             }
           }
@@ -456,7 +455,7 @@ export class Monitor {
           token,
           account,
           currentBalance: currentBalances[i].toString(),
-          target: ethers.utils.parseUnits(target.toString(), decimalValues[i]),
+          target: parseUnits(target.toString(), decimalValues[i]),
         };
       }),
     });
@@ -467,11 +466,11 @@ export class Monitor {
       refillEnabledBalances.map(async ({ chainId, isHubPool, token, account, target, trigger }, i) => {
         const currentBalance = currentBalances[i];
         const decimals = decimalValues[i];
-        const balanceTrigger = ethers.utils.parseUnits(trigger.toString(), decimals);
+        const balanceTrigger = parseUnits(trigger.toString(), decimals);
         const isBelowTrigger = currentBalance.lte(balanceTrigger);
         if (isBelowTrigger) {
           // Fill balance back to target, not trigger.
-          const balanceTarget = ethers.utils.parseUnits(target.toString(), decimals);
+          const balanceTarget = parseUnits(target.toString(), decimals);
           const deficit = balanceTarget.sub(currentBalance);
           let canRefill = await this.balanceAllocator.requestBalanceAllocation(
             chainId,
@@ -541,7 +540,7 @@ export class Monitor {
                 method: "loadEthForL2Calls",
                 args: [],
                 message: "Reloaded ETH in HubPool 🫡!",
-                mrkdwn: `Loaded ${ethers.utils.formatUnits(deficit, decimals)} ETH from ${signerAddress}.`,
+                mrkdwn: `Loaded ${formatUnits(deficit, decimals)} ETH from ${signerAddress}.`,
                 value: deficit,
               });
             } else {
@@ -554,7 +553,7 @@ export class Monitor {
               const receipt = await tx.wait();
               this.logger.info({
                 at: "Monitor#refillBalances",
-                message: `Reloaded ${ethers.utils.formatUnits(
+                message: `Reloaded ${formatUnits(
                   deficit,
                   decimals
                 )} ${nativeSymbolForChain} for ${account} from ${signerAddress} 🫡!`,
diff --git a/src/scripts/validateRootBundle.ts b/src/scripts/validateRootBundle.ts
index 7de4f866b..b21d3255c 100644
--- a/src/scripts/validateRootBundle.ts
+++ b/src/scripts/validateRootBundle.ts
@@ -48,7 +48,7 @@ export async function validate(_logger: winston.Logger, baseSigner: Signer): Pro
   // enough data to limit # of excess historical deposit queries.
   // - SPOKE_ROOTS_LOOKBACK_COUNT unused in this script so set to something < DATAWORKER_FAST_LOOKBACK_COUNT
   // to avoid configuration error.
-  process.env.DATAWORKER_FAST_LOOKBACK_COUNT = "8";
+  process.env.DATAWORKER_FAST_LOOKBACK_COUNT = "10";
   process.env.SPOKE_ROOTS_LOOKBACK_COUNT = "1";
   const { clients, config, dataworker } = await createDataworker(logger, baseSigner);
   logger[startupLogLevel(config)]({
diff --git a/src/utils/BNUtils.ts b/src/utils/BNUtils.ts
index 6fe5d8ad8..ffc1e49be 100644
--- a/src/utils/BNUtils.ts
+++ b/src/utils/BNUtils.ts
@@ -1,4 +1,8 @@
-import { BigNumber } from "ethers";
+// eslint-disable-next-line no-restricted-imports
+import { BigNumber } from "@ethersproject/bignumber";
+
+// eslint-disable-next-line no-restricted-imports
+export * from "@ethersproject/bignumber";
 
 export function bnComparatorDescending(a: BigNumber, b: BigNumber): -1 | 0 | 1 {
   if (b.gt(a)) {
diff --git a/src/utils/CCTPUtils.ts b/src/utils/CCTPUtils.ts
index 172ae3083..69398905e 100644
--- a/src/utils/CCTPUtils.ts
+++ b/src/utils/CCTPUtils.ts
@@ -1,9 +1,10 @@
 import { utils } from "@across-protocol/sdk";
 import { TransactionReceipt } from "@ethersproject/abstract-provider";
 import axios from "axios";
-import { BigNumber, ethers } from "ethers";
+import { ethers } from "ethers";
 import { CONTRACT_ADDRESSES, chainIdsToCctpDomains } from "../common";
 import { EventSearchConfig, paginatedEventQuery } from "./EventUtils";
+import { BigNumber } from "./BNUtils";
 import { bnZero, compareAddressesSimple } from "./SDKUtils";
 import { isDefined } from "./TypeGuards";
 import { getProvider } from "./ProviderUtils";
diff --git a/src/utils/SDKUtils.ts b/src/utils/SDKUtils.ts
index a417c6de7..f8ccb5287 100644
--- a/src/utils/SDKUtils.ts
+++ b/src/utils/SDKUtils.ts
@@ -27,7 +27,10 @@ export const {
   fillStatusArray,
   fixedPointAdjustment,
   forEachAsync,
+  formatEther,
+  formatUnits,
   mapAsync,
+  parseUnits,
   filterAsync,
   toBN,
   bnToHex,
diff --git a/src/utils/TokenUtils.ts b/src/utils/TokenUtils.ts
index 8e8ddb99e..1ce1c7e63 100644
--- a/src/utils/TokenUtils.ts
+++ b/src/utils/TokenUtils.ts
@@ -1,7 +1,9 @@
+import { TOKEN_SYMBOLS_MAP } from "@across-protocol/constants";
 import { constants, utils } from "@across-protocol/sdk";
 import { CONTRACT_ADDRESSES } from "../common";
-import { BigNumberish, utils as ethersUtils } from "ethers";
-import { TOKEN_SYMBOLS_MAP } from "@across-protocol/constants";
+import { BigNumberish } from "./BNUtils";
+import { formatUnits } from "./SDKUtils";
+
 const { ZERO_ADDRESS } = constants;
 
 export const { fetchTokenInfo, getL2TokenAddresses } = utils;
@@ -18,5 +20,5 @@ export function getNativeTokenAddressForChain(chainId: number): string {
  */
 export function formatUnitsForToken(symbol: string, amount: BigNumberish): string {
   const decimals = (TOKEN_SYMBOLS_MAP[symbol]?.decimals as number) ?? 18;
-  return ethersUtils.formatUnits(amount, decimals);
+  return formatUnits(amount, decimals);
 }
diff --git a/src/utils/TransactionUtils.ts b/src/utils/TransactionUtils.ts
index 494256a63..086d4e47c 100644
--- a/src/utils/TransactionUtils.ts
+++ b/src/utils/TransactionUtils.ts
@@ -221,6 +221,6 @@ export function getTarget(targetAddress: string):
   }
 }
 
-function scaleByNumber(amount: ethers.BigNumber, scaling: number) {
+function scaleByNumber(amount: BigNumber, scaling: number) {
   return amount.mul(toBNWei(scaling)).div(fixedPoint);
 }
diff --git a/src/utils/index.ts b/src/utils/index.ts
index 4c3e8f0bc..a2fabbf0f 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -14,8 +14,6 @@ export {
   providers,
   utils,
   BaseContract,
-  BigNumber,
-  BigNumberish,
   Contract,
   ContractFactory,
   Event,
diff --git a/test/Dataworker.buildRoots.ts b/test/Dataworker.buildRoots.ts
index 9dba449f7..3af6f3c13 100644
--- a/test/Dataworker.buildRoots.ts
+++ b/test/Dataworker.buildRoots.ts
@@ -5,7 +5,6 @@ import { assert, bnZero, fixedPointAdjustment } from "../src/utils";
 import { amountToDeposit, destinationChainId, mockTreeRoot, originChainId, repaymentChainId } from "./constants";
 import { setupFastDataworker } from "./fixtures/Dataworker.Fixture";
 import {
-  BigNumber,
   Contract,
   SignerWithAddress,
   buildV3SlowRelayLeaves,
@@ -279,7 +278,7 @@ describe("Dataworker: Build merkle roots", async function () {
     const expectedRunningBalances: RunningBalances = {
       // Note: There should be no origin chain entry here since there were no deposits.
       [originChainId]: {
-        [l1Token_1.address]: BigNumber.from(0),
+        [l1Token_1.address]: bnZero,
       },
     };
     expect(expectedRunningBalances).to.deep.equal(merkleRoot1.runningBalances);
diff --git a/test/InventoryClient.InventoryRebalance.ts b/test/InventoryClient.InventoryRebalance.ts
index 424a9ff4f..d2d55a8cf 100644
--- a/test/InventoryClient.InventoryRebalance.ts
+++ b/test/InventoryClient.InventoryRebalance.ts
@@ -27,10 +27,11 @@ import {
   ERC20,
   fixedPointAdjustment as fixedPoint,
   getNetworkName,
+  parseUnits,
   TOKEN_SYMBOLS_MAP,
 } from "../src/utils";
 
-const toMegaWei = (num: string | number | BigNumber) => ethers.utils.parseUnits(num.toString(), 6);
+const toMegaWei = (num: string | number | BigNumber) => parseUnits(num.toString(), 6);
 
 let hubPoolClient: MockHubPoolClient, adapterManager: MockAdapterManager, tokenClient: MockTokenClient;
 let bundleDataClient: MockBundleDataClient;
diff --git a/test/InventoryClient.RefundChain.ts b/test/InventoryClient.RefundChain.ts
index 9906214c4..ed34ac41f 100644
--- a/test/InventoryClient.RefundChain.ts
+++ b/test/InventoryClient.RefundChain.ts
@@ -19,7 +19,7 @@ import {
 import { ConfigStoreClient, InventoryClient } from "../src/clients"; // Tested
 import { CrossChainTransferClient } from "../src/clients/bridges";
 import { Deposit, InventoryConfig } from "../src/interfaces";
-import { CHAIN_IDs, ZERO_ADDRESS, bnZero, getNetworkName, TOKEN_SYMBOLS_MAP } from "../src/utils";
+import { CHAIN_IDs, ZERO_ADDRESS, bnZero, getNetworkName, parseUnits, TOKEN_SYMBOLS_MAP } from "../src/utils";
 import {
   MockAdapterManager,
   MockBundleDataClient,
@@ -51,7 +51,7 @@ describe("InventoryClient: Refund chain selection", async function () {
       l2TokensForUsdc[chainId] = TOKEN_SYMBOLS_MAP["USDC.e"].addresses[chainId];
     });
 
-  const toMegaWei = (num: string | number | BigNumber) => ethers.utils.parseUnits(num.toString(), 6);
+  const toMegaWei = (num: string | number | BigNumber) => parseUnits(num.toString(), 6);
   // Configure thresholds percentages as 10% optimism, 5% polygon and 5% Arbitrum with a target being threshold +2%.
   const targetOverageBuffer = toWei(1);
   const inventoryConfig: InventoryConfig = {
diff --git a/test/TransactionClient.ts b/test/TransactionClient.ts
index aba9e933e..05f1dfc8b 100644
--- a/test/TransactionClient.ts
+++ b/test/TransactionClient.ts
@@ -1,6 +1,5 @@
-import { BigNumber } from "ethers";
 import { AugmentedTransaction } from "../src/clients";
-import { isDefined, TransactionResponse, TransactionSimulationResult } from "../src/utils";
+import { BigNumber, isDefined, TransactionResponse, TransactionSimulationResult } from "../src/utils";
 import { CHAIN_ID_TEST_LIST as chainIds } from "./constants";
 import { MockedTransactionClient, txnClientPassResult } from "./mocks/MockTransactionClient";
 import { createSpyLogger, Contract, expect, randomAddress, winston, toBN } from "./utils";
diff --git a/test/mocks/MockCrossChainTransferClient.ts b/test/mocks/MockCrossChainTransferClient.ts
index 66bb70ecc..a8ca0da2a 100644
--- a/test/mocks/MockCrossChainTransferClient.ts
+++ b/test/mocks/MockCrossChainTransferClient.ts
@@ -1,7 +1,7 @@
-import { BigNumber } from "ethers";
+import { BigNumber, bnZero } from "../../src/utils";
 import { CrossChainTransferClient } from "../../src/clients/bridges";
 export class MockCrossChainTransferClient extends CrossChainTransferClient {
-  crossChainTransferAmount: BigNumber = BigNumber.from(0);
+  crossChainTransferAmount = bnZero;
   constructor() {
     super(null, null, null);
   }
diff --git a/test/mocks/MockInventoryClient.ts b/test/mocks/MockInventoryClient.ts
index 944723c3d..2c0b143a2 100644
--- a/test/mocks/MockInventoryClient.ts
+++ b/test/mocks/MockInventoryClient.ts
@@ -1,11 +1,12 @@
 import { Deposit, InventoryConfig } from "../../src/interfaces";
 import { BundleDataClient, HubPoolClient, InventoryClient, Rebalance, TokenClient } from "../../src/clients";
 import { AdapterManager, CrossChainTransferClient } from "../../src/clients/bridges";
-import { BigNumber } from "ethers";
+import { BigNumber, bnZero } from "../../src/utils";
 import winston from "winston";
+
 export class MockInventoryClient extends InventoryClient {
   possibleRebalances: Rebalance[] = [];
-  balanceOnChain: BigNumber | undefined = BigNumber.from(0);
+  balanceOnChain: BigNumber | undefined = bnZero;
   excessRunningBalancePcts: { [l1Token: string]: { [chainId: number]: BigNumber } } = {};
 
   constructor(
diff --git a/test/mocks/MockTransactionClient.ts b/test/mocks/MockTransactionClient.ts
index c337a8b16..e51c86ed4 100644
--- a/test/mocks/MockTransactionClient.ts
+++ b/test/mocks/MockTransactionClient.ts
@@ -1,7 +1,7 @@
-import { BigNumber, ethers } from "ethers";
+import { ethers } from "ethers";
 import { random } from "lodash";
 import { AugmentedTransaction, TransactionClient } from "../../src/clients";
-import { TransactionResponse, TransactionSimulationResult } from "../../src/utils";
+import { BigNumber, TransactionResponse, TransactionSimulationResult } from "../../src/utils";
 import { toBNWei, winston } from "../utils";
 
 export const txnClientPassResult = "pass";
diff --git a/test/utils/utils.ts b/test/utils/utils.ts
index b76f84f88..409210a51 100644
--- a/test/utils/utils.ts
+++ b/test/utils/utils.ts
@@ -3,14 +3,14 @@ import { TokenRolesEnum } from "@uma/common";
 import { SpyTransport, bigNumberFormatter } from "@uma/logger";
 import { AcrossConfigStore, FakeContract } from "@across-protocol/contracts";
 import { constants, utils as sdkUtils } from "@across-protocol/sdk";
-import { BigNumber, Contract, providers } from "ethers";
+import { Contract, providers } from "ethers";
 import chai, { assert, expect } from "chai";
 import chaiExclude from "chai-exclude";
 import sinon from "sinon";
 import winston from "winston";
 import { GLOBAL_CONFIG_STORE_KEYS } from "../../src/clients";
 import { Deposit, DepositWithBlock, FillWithBlock, SlowFillLeaf } from "../../src/interfaces";
-import { isDefined, spreadEvent, toBN, toBNWei, toWei, utf8ToHex, ZERO_ADDRESS } from "../../src/utils";
+import { BigNumber, isDefined, spreadEvent, toBN, toBNWei, toWei, utf8ToHex, ZERO_ADDRESS } from "../../src/utils";
 import {
   DEFAULT_BLOCK_RANGE_FOR_CHAIN,
   MAX_L1_TOKENS_PER_POOL_REBALANCE_LEAF,