diff --git a/src/mempool/mempool.ts b/src/mempool/mempool.ts
index 5f788805..66329a2c 100644
--- a/src/mempool/mempool.ts
+++ b/src/mempool/mempool.ts
@@ -355,7 +355,7 @@ export class Mempool {
         })
 
         if (conflicting) {
-            const { userOpInfo, reason } = conflicting
+            const { userOpInfo, conflictReason } = conflicting
             const conflictingUserOp = userOpInfo.userOp
 
             const hasHigherPriorityFee =
@@ -372,10 +372,17 @@ export class Mempool {
             const hasHigherFees = hasHigherPriorityFee && hasHigherMaxFee
 
             if (!hasHigherFees) {
-                const message =
-                    reason === "conflicting_deployment"
-                        ? "AA10 sender already constructed: A conflicting userOperation with initCode for this sender is already in the mempool"
-                        : "AA25 invalid account nonce: User operation already present in mempool"
+                let message: string
+                if (conflictReason === "conflicting_deployment") {
+                    message =
+                        "AA10 sender already constructed: A conflicting userOperation with initCode for this sender is already in the mempool"
+                } else if (conflictReason === "conflicting_7702_auth") {
+                    message =
+                        "Sender already has an inflight EIP-7702 authorization"
+                } else {
+                    message =
+                        "AA25 invalid account nonce: User operation already present in mempool"
+                }
 
                 // Re-add to outstanding as it wasn't replaced
                 await this.store.addOutstanding({
diff --git a/src/store/outstanding/memory.ts b/src/store/outstanding/memory.ts
index 88ca5277..21e6d792 100644
--- a/src/store/outstanding/memory.ts
+++ b/src/store/outstanding/memory.ts
@@ -87,41 +87,56 @@ export class MemoryOutstanding implements OutstandingStore {
     ): Promise<ConflictingOutstandingType> {
         const outstandingOps = this.dump()
 
-        let conflictingReason: ConflictingOutstandingType
+        for (const existingUserOpInfo of outstandingOps) {
+            const { userOp: existingUserOp, userOpHash: existingUserOpHash } =
+                existingUserOpInfo
 
-        for (const userOpInfo of outstandingOps) {
-            const { userOp: mempoolUserOp } = userOpInfo
+            const isSameSender = existingUserOp.sender === userOp.sender
 
-            const isSameSender = mempoolUserOp.sender === userOp.sender
-            if (isSameSender && mempoolUserOp.nonce === userOp.nonce) {
-                const removed = await this.remove([userOpInfo.userOpHash])
+            // Check each conflict type.
+            const isConflictingNonce =
+                isSameSender && existingUserOp.nonce === userOp.nonce
+
+            const isConflictingEip7702Auth =
+                isSameSender && userOp.eip7702Auth && existingUserOp.eip7702Auth
+
+            const isConflictingDeployment =
+                isSameSender &&
+                isDeployment(userOp) &&
+                isDeployment(existingUserOp)
+
+            if (isConflictingNonce) {
+                const removed = await this.remove([existingUserOpHash])
                 if (removed.length > 0) {
-                    conflictingReason = {
-                        reason: "conflicting_nonce",
+                    return {
+                        conflictReason: "conflicting_nonce",
                         userOpInfo: removed[0]
                     }
                 }
-                break
             }
 
-            const isConflictingDeployment =
-                isSameSender &&
-                isDeployment(userOp) &&
-                isDeployment(mempoolUserOp)
+            if (isConflictingEip7702Auth) {
+                const removed = await this.remove([existingUserOpHash])
+                if (removed.length > 0) {
+                    return {
+                        conflictReason: "conflicting_7702_auth",
+                        userOpInfo: removed[0]
+                    }
+                }
+            }
 
             if (isConflictingDeployment) {
-                const removed = await this.remove([userOpInfo.userOpHash])
+                const removed = await this.remove([existingUserOpHash])
                 if (removed.length > 0) {
-                    conflictingReason = {
-                        reason: "conflicting_deployment",
+                    return {
+                        conflictReason: "conflicting_deployment",
                         userOpInfo: removed[0]
                     }
                 }
-                break
             }
         }
 
-        return conflictingReason
+        return undefined
     }
 
     async contains(userOpHash: HexData32): Promise<boolean> {
diff --git a/src/store/outstanding/redis.ts b/src/store/outstanding/redis.ts
index 428e41b3..24a72bbe 100644
--- a/src/store/outstanding/redis.ts
+++ b/src/store/outstanding/redis.ts
@@ -30,6 +30,7 @@ class RedisOutstandingQueue implements OutstandingStore {
     private readonly readyQueue: string // Queue of userOpHashes (sorted by composite of userOp.nonceSeq + userOp.maxFeePerGas)
     private readonly userOpHashMap: string // userOpHash -> boolean
     private readonly deploymentHashMap: string // sender -> deployment userOpHash
+    private readonly eip7702AuthHashMap: string // sender -> eip7702Auth userOpHash
     private readonly senderNonceQueueTtl: number // TTL for sender nonce queues in seconds
 
     constructor({
@@ -51,6 +52,7 @@ class RedisOutstandingQueue implements OutstandingStore {
         this.senderNonceKeyPrefix = `${redisPrefix}:sender`
         this.userOpHashMap = `${redisPrefix}:userop-hash`
         this.deploymentHashMap = `${redisPrefix}:deployment-senders`
+        this.eip7702AuthHashMap = `${redisPrefix}:eip7702-auth-senders`
 
         // Calculate TTL for sender nonce queues (10 blocks worth of time)
         this.senderNonceQueueTtl = config.blockTime * 10
@@ -93,7 +95,7 @@ class RedisOutstandingQueue implements OutstandingStore {
 
             if (removedUserOps.length > 0) {
                 return {
-                    reason: "conflicting_nonce" as const,
+                    conflictReason: "conflicting_nonce" as const,
                     userOpInfo: removedUserOps[0]
                 }
             }
@@ -113,7 +115,28 @@ class RedisOutstandingQueue implements OutstandingStore {
 
                 if (removedUserOps.length > 0) {
                     return {
-                        reason: "conflicting_deployment" as const,
+                        conflictReason: "conflicting_deployment" as const,
+                        userOpInfo: removedUserOps[0]
+                    }
+                }
+            }
+        }
+
+        // Check for conflicting EIP-7702 auth.
+        if (userOp.eip7702Auth) {
+            const existingEip7702AuthHash = (await this.redis.hget(
+                this.eip7702AuthHashMap,
+                sender
+            )) as HexData32 | null
+
+            if (existingEip7702AuthHash) {
+                const removedUserOps = await this.remove([
+                    existingEip7702AuthHash
+                ])
+
+                if (removedUserOps.length > 0) {
+                    return {
+                        conflictReason: "conflicting_7702_auth" as const,
                         userOpInfo: removedUserOps[0]
                     }
                 }
@@ -156,6 +179,15 @@ class RedisOutstandingQueue implements OutstandingStore {
             if (isDeployment(userOp)) {
                 pipeline.hset(this.deploymentHashMap, userOp.sender, userOpHash)
             }
+
+            // Add sender to eip7702Auth hash if this has eip7702Auth.
+            if (userOp.eip7702Auth) {
+                pipeline.hset(
+                    this.eip7702AuthHashMap,
+                    userOp.sender,
+                    userOpHash
+                )
+            }
         }
 
         await pipeline.exec()
@@ -205,6 +237,11 @@ class RedisOutstandingQueue implements OutstandingStore {
                 removalPipeline.hdel(this.deploymentHashMap, userOp.sender)
             }
 
+            // Remove sender from eip7702Auth hash if this had eip7702Auth.
+            if (userOp.eip7702Auth) {
+                removalPipeline.hdel(this.eip7702AuthHashMap, userOp.sender)
+            }
+
             removedUserOps.push(userOpInfo)
         }
 
diff --git a/src/store/outstanding/types.ts b/src/store/outstanding/types.ts
index 3db86d0a..b0b4ec86 100644
--- a/src/store/outstanding/types.ts
+++ b/src/store/outstanding/types.ts
@@ -2,7 +2,10 @@ import type { HexData32, UserOpInfo, UserOperation } from "@alto/types"
 
 export type ConflictingOutstandingType =
     | {
-          reason: "conflicting_nonce" | "conflicting_deployment"
+          conflictReason:
+              | "conflicting_nonce"
+              | "conflicting_deployment"
+              | "conflicting_7702_auth"
           userOpInfo: UserOpInfo
       }
     | undefined