diff --git a/mainnet/2025-12-01-accept-smart-escrow-ownership/.env b/mainnet/2025-12-01-accept-smart-escrow-ownership/.env
new file mode 100644
index 00000000..09e51227
--- /dev/null
+++ b/mainnet/2025-12-01-accept-smart-escrow-ownership/.env
@@ -0,0 +1,21 @@
+OP_COMMIT=d09c836f818c73ae139f60b717654c4e53712743
+BASE_CONTRACTS_COMMIT=9526d38b63be2ee10fc905dee60f0b2a0a17e89e
+
+# TODO: Update to set the Safe receiving ownership
+OWNER_SAFE=TODO
+
+# CB Safe receiving ownership
+CB_SAFE=0x9C4a57Feb77e294Fd7BF5EBE9AB01CAA0a90A110
+# OP Safe receiving ownership
+OP_SAFE=0x9BA6e03D8B90dE867373Db8cF1A58d2F7F006b3A
+
+# Update to be a member of the CB Safe receiving ownership
+CB_SIGNER=0x6CD3850756b7894774Ab715D136F9dD02837De50
+# Update to be a member of the OP Safe receiving ownership
+OP_SIGNER=0x42d27eEA1AD6e22Af6284F609847CB3Cd56B9c64
+
+L2_GAS_LIMIT=200000
+SMART_ESCROW=0xb3C2f9fC2727078EC3A2255410e83BA5B62c5B5f
+PORTAL=0xbEb5Fc579115071764c7423A4f12eDde41f106Ed
+
+RECORD_STATE_DIFF=true
diff --git a/mainnet/2025-12-01-accept-smart-escrow-ownership/FACILITATORS.md b/mainnet/2025-12-01-accept-smart-escrow-ownership/FACILITATORS.md
new file mode 100644
index 00000000..8e282baa
--- /dev/null
+++ b/mainnet/2025-12-01-accept-smart-escrow-ownership/FACILITATORS.md
@@ -0,0 +1,54 @@
+#### Execute the transaction
+
+## 1. Update repo:
+
+```bash
+cd contract-deployments
+git pull
+cd mainnet/2025-12-01-accept-smart-escrow-ownership
+make deps
+```
+
+1. Collect outputs from all participating signers.
+1. Concatenate all signatures and export it as the `SIGNATURES`
+   environment variable, i.e. `export
+SIGNATURES="[SIGNATURE1][SIGNATURE2]..."`.
+1. Run the `make execute` or `make approve` command as described below to execute the transaction.
+
+For example, if the quorum is 3 and you get the following outputs:
+
+```shell
+Data:  0xDEADBEEF
+Signer: 0xC0FFEE01
+Signature: AAAA
+```
+
+```shell
+Data:  0xDEADBEEF
+Signer: 0xC0FFEE02
+Signature: BBBB
+```
+
+```shell
+Data:  0xDEADBEEF
+Signer: 0xC0FFEE03
+Signature: CCCC
+```
+
+Coinbase facilitator:
+
+```bash
+SIGNATURES=AAAABBBBCCCC make approve-cb
+```
+
+Optimism facilitator:
+
+```bash
+SIGNATURES=AAAABBBBCCCC make approve-op
+```
+
+Once the signatures have been submitted approving the transaction for all nested Safes run:
+
+```bash
+make execute
+```
diff --git a/mainnet/2025-12-01-accept-smart-escrow-ownership/Makefile b/mainnet/2025-12-01-accept-smart-escrow-ownership/Makefile
new file mode 100644
index 00000000..0a4b79df
--- /dev/null
+++ b/mainnet/2025-12-01-accept-smart-escrow-ownership/Makefile
@@ -0,0 +1,48 @@
+include ../../Makefile
+include ../../Multisig.mk
+include ../.env
+include .env
+
+ifndef LEDGER_ACCOUNT
+override LEDGER_ACCOUNT = 0
+endif
+
+RPC_URL = $(L1_RPC_URL)
+SCRIPT_NAME = AcceptSmartEscrowOwnership
+
+.PHONY: gen-validation
+gen-validation: gen-validation-cb gen-validation-op
+
+.PHONY: gen-validation-cb
+gen-validation-cb: checkout-signer-tool run-script-cb
+
+.PHONY: gen-validation-op
+gen-validation-op: checkout-signer-tool run-script-op
+
+.PHONY: run-script-cb
+run-script-cb:
+	cd $(SIGNER_TOOL_PATH); \
+	npm ci; \
+	bun run scripts/genValidationFile.ts --rpc-url $(RPC_URL) \
+	--workdir .. --forge-cmd 'forge script --rpc-url $(RPC_URL) \
+	$(SCRIPT_NAME) --sig "sign(address[])" "[$(CB_SAFE)]" --sender $(CB_SIGNER)' --out ../validations/cb-signer.json;
+
+.PHONY: run-script-op
+run-script-op:
+	cd $(SIGNER_TOOL_PATH); \
+	npm ci; \
+	bun run scripts/genValidationFile.ts --rpc-url $(RPC_URL) \
+	--workdir .. --forge-cmd 'forge script --rpc-url $(RPC_URL) \
+	$(SCRIPT_NAME) --sig "sign(address[])" "[$(OP_SAFE)]" --sender $(OP_SIGNER)' --out ../validations/op-signer.json;
+
+.PHONY: approve-cb
+approve-cb:
+	$(call MULTISIG_APPROVE,$(CB_SAFE),$(SIGNATURES))
+
+.PHONY: approve-op
+approve-op:
+	$(call MULTISIG_APPROVE,$(OP_SAFE),$(SIGNATURES))
+
+.PHONY: execute
+execute:
+	$(call MULTISIG_EXECUTE,0x)
diff --git a/mainnet/2025-12-01-accept-smart-escrow-ownership/README.md b/mainnet/2025-12-01-accept-smart-escrow-ownership/README.md
new file mode 100644
index 00000000..d9064ab2
--- /dev/null
+++ b/mainnet/2025-12-01-accept-smart-escrow-ownership/README.md
@@ -0,0 +1,63 @@
+# Accept SmartEscrow Ownership
+
+Status: READY TO SIGN
+
+## Description
+
+This task finalises the `SmartEscrow` ownership transfer that was initiated in [`2025-04-07-init-smart-escrow-ownership-transfer`](https://github.com/base/contract-deployments/blob/main/mainnet/2025-04-07-init-smart-escrow-ownership-transfer/README.md). The pending admin is the L1 `ProxyAdmin` owner Safe (aliased on L2); after the mandatory delay expires we must relay an L1 transaction that calls `AccessControlDefaultAdminRules.acceptDefaultAdminTransfer()` on the SmartEscrow contract (`0xb3C2f9fC2727078EC3A2255410e83BA5B62c5B5f`).
+
+We send this call from the L1 owner Safe by depositing a transaction through the Optimism Portal (`0xbEb5Fc579115071764c7423A4f12eDde41f106Ed`) with the Safe as the sender. The call includes no ETH transfer to SmartEscrow, but the Safe must cover the L2 execution fee (`L2_FEE`).
+
+Environment variables:
+
+- `OWNER_SAFE`: L1 Safe that owns SmartEscrow after acceptance.
+- `SMART_ESCROW`: SmartEscrow contract on OP Mainnet.
+- `PORTAL`: Optimism Portal on Ethereum mainnet.
+- `L2_GAS_LIMIT`: Gas limit forwarded to L2 for `acceptDefaultAdminTransfer`.
+- `L2_FEE`: ETH sent to the portal to pay the L2 execution fee (set at runtime).
+
+## Procedure
+
+## Install dependencies
+
+### 1. Update foundry
+
+```bash
+foundryup
+```
+
+### 2. Install Node.js if needed
+
+First, check if you have node installed
+
+```bash
+node --version
+```
+
+If you see a version output from the above command, you can move on. Otherwise, install node
+
+```bash
+brew install node
+```
+
+## Approving the Update transaction
+
+### 1. Update repo:
+
+```bash
+cd contract-deployments
+git pull
+```
+
+### 2. Run the signing tool (NOTE: do not enter the task directory. Run this command from the project's root).
+
+```bash
+make sign-task
+```
+
+### 3. Open the UI at [http://localhost:3000](http://localhost:3000)
+
+Be sure to select the correct task user from the list of available users to sign.
+After completion, the signer tool can be closed by using Ctrl + C.
+
+### 4. Send the signature to the facilitator
diff --git a/mainnet/2025-12-01-accept-smart-escrow-ownership/foundry.toml b/mainnet/2025-12-01-accept-smart-escrow-ownership/foundry.toml
new file mode 100644
index 00000000..ba63c28b
--- /dev/null
+++ b/mainnet/2025-12-01-accept-smart-escrow-ownership/foundry.toml
@@ -0,0 +1,27 @@
+[profile.default]
+src = 'src'
+out = 'out'
+libs = ['lib']
+broadcast = 'records'
+fs_permissions = [{ access = "read-write", path = "./" }]
+optimizer = true
+optimizer_runs = 999999
+solc_version = "0.8.15"
+via-ir = false
+remappings = [
+    '@eth-optimism-bedrock/=lib/optimism/packages/contracts-bedrock/',
+    '@openzeppelin/contracts/=lib/openzeppelin-contracts/contracts',
+    '@openzeppelin/contracts-upgradeable/=lib/openzeppelin-contracts-upgradeable/contracts',
+    '@rari-capital/solmate/=lib/solmate/',
+    '@base-contracts/=lib/base-contracts',
+    '@solady/=lib/solady/src/',
+    '@lib-keccak/=lib/lib-keccak/contracts/lib/',
+    "interfaces/=lib/optimism/packages/contracts-bedrock/interfaces",
+    "src/dispute/=lib/optimism/packages/contracts-bedrock/src/dispute",
+    "src/libraries/=lib/optimism/packages/contracts-bedrock/src/libraries",
+    "src/cannon/=lib/optimism/packages/contracts-bedrock/src/cannon",
+    "src/L1/=lib/optimism/packages/contracts-bedrock/src/L1",
+    "scripts/=lib/optimism/packages/contracts-bedrock/scripts",
+]
+
+# See more config options https://github.com/foundry-rs/foundry/tree/master/config
diff --git a/mainnet/2025-12-01-accept-smart-escrow-ownership/script/AcceptSmartEscrowOwnership.s.sol b/mainnet/2025-12-01-accept-smart-escrow-ownership/script/AcceptSmartEscrowOwnership.s.sol
new file mode 100644
index 00000000..e704281d
--- /dev/null
+++ b/mainnet/2025-12-01-accept-smart-escrow-ownership/script/AcceptSmartEscrowOwnership.s.sol
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.15;
+
+import {Vm} from "forge-std/Vm.sol";
+import {IMulticall3} from "forge-std/interfaces/IMulticall3.sol";
+
+import {MultisigScript} from "@base-contracts/script/universal/MultisigScript.sol";
+import {Simulation} from "@base-contracts/script/universal/Simulation.sol";
+import {IOptimismPortal2} from "@eth-optimism-bedrock/interfaces/L1/IOptimismPortal2.sol";
+import {AccessControlDefaultAdminRules} from "@openzeppelin/contracts/access/AccessControlDefaultAdminRules.sol";
+
+contract AcceptSmartEscrowOwnership is MultisigScript {
+    address internal immutable OWNER_SAFE;
+    address internal immutable PORTAL;
+    address internal immutable SMART_ESCROW;
+    uint64 internal immutable L2_GAS_LIMIT;
+
+    constructor() {
+        OWNER_SAFE = vm.envAddress("OWNER_SAFE");
+        PORTAL = vm.envAddress("PORTAL");
+        SMART_ESCROW = vm.envAddress("SMART_ESCROW");
+        L2_GAS_LIMIT = uint64(vm.envUint("L2_GAS_LIMIT"));
+
+        require(OWNER_SAFE != address(0), "OWNER_SAFE env var not set");
+        require(PORTAL != address(0), "PORTAL env var not set");
+        require(SMART_ESCROW != address(0), "SMART_ESCROW env var not set");
+    }
+
+    function setUp() public view {
+        require(L2_GAS_LIMIT > 0, "L2_GAS_LIMIT must be > 0");
+    }
+
+    function _buildCalls() internal view override returns (IMulticall3.Call3Value[] memory calls) {
+        calls = new IMulticall3.Call3Value[](1);
+
+        address payable target = SMART_ESCROW;
+        uint256 value = 0;
+        uint64 gasLimit = L2_GAS_LIMIT;
+        bool isCreation = false;
+        bytes memory acceptData = abi.encodeCall(AccessControlDefaultAdminRules.acceptDefaultAdminTransfer, ());
+
+        calls[0] = IMulticall3.Call3Value({
+            target: PORTAL,
+            allowFailure: false,
+            callData: abi.encodeCall(
+                IOptimismPortal2.depositTransaction, (target, value, gasLimit, isCreation, acceptData)
+            ),
+            value: 0
+        });
+    }
+
+    function _postCheck(Vm.AccountAccess[] memory, Simulation.Payload memory) internal view override {}
+
+    function _ownerSafe() internal view override returns (address) {
+        return OWNER_SAFE;
+    }
+}
diff --git a/mainnet/2025-12-01-accept-smart-escrow-ownership/validations/base-signer.json b/mainnet/2025-12-01-accept-smart-escrow-ownership/validations/base-signer.json
new file mode 100644
index 00000000..bd29e4f1
--- /dev/null
+++ b/mainnet/2025-12-01-accept-smart-escrow-ownership/validations/base-signer.json
@@ -0,0 +1,78 @@
+{
+  "cmd": "forge script --rpc-url https://eth-mainnet.public.blastapi.io AcceptSmartEscrowOwnership --sig sign(address[]) [] --sender 0x1841CB3C2ce6870D0417844C817849da64E6e937",
+  "ledgerId": 0,
+  "rpcUrl": "https://eth-mainnet.public.blastapi.io",
+  "expectedDomainAndMessageHashes": {
+    "address": "0x14536667Cd30e52C0b458BaACcB9faDA7046E056",
+    "domainHash": "0xf3474c66ee08325b410c3f442c878d01ec97dd55a415a307e9d7d2ea24336289",
+    "messageHash": "0x70129c7514a5fba8c013faa35eb4e84a25e6185010800c50faafc73e727c489e"
+  },
+  "stateOverrides": [
+    {
+      "name": "Incident Safe - Mainnet",
+      "address": "0x14536667cd30e52c0b458baaccb9fada7046e056",
+      "overrides": [
+        {
+          "key": "0x0000000000000000000000000000000000000000000000000000000000000004",
+          "value": "0x0000000000000000000000000000000000000000000000000000000000000001",
+          "description": "Override the threshold to 1 so the transaction simulation can occur.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x95d2e559ecc4123c992191c982fcacdff23ac220c7a38b92ea163a056c1c3dd0",
+          "value": "0x0000000000000000000000000000000000000000000000000000000000000001",
+          "description": "Simulates an approval from msg.sender in order for the task simulation to succeed.",
+          "allowDifference": false
+        }
+      ]
+    }
+  ],
+  "stateChanges": [
+    {
+      "name": "Incident Safe - Mainnet",
+      "address": "0x14536667cd30e52c0b458baaccb9fada7046e056",
+      "changes": [
+        {
+          "key": "0x0000000000000000000000000000000000000000000000000000000000000005",
+          "before": "0x000000000000000000000000000000000000000000000000000000000000005f",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000060",
+          "description": "Increments the nonce",
+          "allowDifference": false
+        }
+      ]
+    },
+    {
+      "name": "Optimism Portal",
+      "address": "0xbeb5fc579115071764c7423a4f12edde41f106ed",
+      "changes": [
+        {
+          "key": "0x0000000000000000000000000000000000000000000000000000000000000001",
+          "before": "0x00000000016cf17500000000000afd1d0000000000000000000000003b9aca00",
+          "after": "0x00000000016cf1890000000000030d400000000000000000000000003b9aca00",
+          "description": "Updates the portal's ResourceMetering params with the latest block number and deposit gas usage.",
+          "allowDifference": true
+        }
+      ]
+    }
+  ],
+  "balanceChanges": [
+    {
+      "name": "Incident Safe - Mainnet",
+      "address": "0x14536667cd30e52c0b458baaccb9fada7046e056",
+      "field": "ETH Balance (wei)",
+      "before": "0x0000000000000000000000000000000000000000000000001a4e86c4783b08bb",
+      "after": "0x0000000000000000000000000000000000000000000000001a4da364cf0968bb",
+      "description": "ETH balance change for this account",
+      "allowDifference": false
+    },
+    {
+      "name": "Optimism ETHLockbox",
+      "address": "0x322b47ff1fa8d5611f761e3e275c45b71b294d43",
+      "field": "ETH Balance (wei)",
+      "before": "0x000000000000000000000000000000000000000000002b0d1bc83b08a187dc11",
+      "after": "0x000000000000000000000000000000000000000000002b0d1bc91e684ab97c11",
+      "description": "ETH balance change for this account",
+      "allowDifference": true
+    }
+  ]
+}