diff --git a/Mixin.xcodeproj/project.pbxproj b/Mixin.xcodeproj/project.pbxproj
index 756ceabce..4172e3113 100644
--- a/Mixin.xcodeproj/project.pbxproj
+++ b/Mixin.xcodeproj/project.pbxproj
@@ -1220,6 +1220,7 @@
 		94F237562C6915B70057D1AB /* PriceHistory.swift in Sources */ = {isa = PBXBuildFile; fileRef = 94F237552C6915B70057D1AB /* PriceHistory.swift */; };
 		94F2375C2C691D5C0057D1AB /* TokenPriceChartCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = 94F2375A2C691D5C0057D1AB /* TokenPriceChartCell.swift */; };
 		94F2375D2C691D5C0057D1AB /* TokenPriceChartCell.xib in Resources */ = {isa = PBXBuildFile; fileRef = 94F2375B2C691D5C0057D1AB /* TokenPriceChartCell.xib */; };
+		94F35A602D255B61001BCAE7 /* Invoice.swift in Sources */ = {isa = PBXBuildFile; fileRef = 94F35A5F2D255B5F001BCAE7 /* Invoice.swift */; };
 		94F36AC626CA59B300AC30A5 /* PhoneNumberValidator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 94F36AC526CA59B300AC30A5 /* PhoneNumberValidator.swift */; };
 		94F952582AE616F40025B995 /* TransferOutViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 94F952572AE616F40025B995 /* TransferOutViewController.swift */; };
 		94F9525D2AE6174A0025B995 /* TransferOutView.xib in Resources */ = {isa = PBXBuildFile; fileRef = 94F9525C2AE6174A0025B995 /* TransferOutView.xib */; };
@@ -2715,6 +2716,7 @@
 		94F237552C6915B70057D1AB /* PriceHistory.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PriceHistory.swift; sourceTree = "<group>"; };
 		94F2375A2C691D5C0057D1AB /* TokenPriceChartCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TokenPriceChartCell.swift; sourceTree = "<group>"; };
 		94F2375B2C691D5C0057D1AB /* TokenPriceChartCell.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = TokenPriceChartCell.xib; sourceTree = "<group>"; };
+		94F35A5F2D255B5F001BCAE7 /* Invoice.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Invoice.swift; sourceTree = "<group>"; };
 		94F36AC526CA59B300AC30A5 /* PhoneNumberValidator.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PhoneNumberValidator.swift; sourceTree = "<group>"; };
 		94F952572AE616F40025B995 /* TransferOutViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TransferOutViewController.swift; sourceTree = "<group>"; };
 		94F9525C2AE6174A0025B995 /* TransferOutView.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = TransferOutView.xib; sourceTree = "<group>"; };
@@ -4230,6 +4232,7 @@
 				940DC5912B075E03009A15D1 /* SafePaymentURL.swift */,
 				94BD7E762B2983CA0004576D /* MultisigURL.swift */,
 				94EE1C002B4C647500BE9AD1 /* CodeURL.swift */,
+				94F35A5F2D255B5F001BCAE7 /* Invoice.swift */,
 				94C5A8922B2157CE00201CDA /* Payment.swift */,
 				94C6987A2B23257B002377EA /* PaymentPrecondition.swift */,
 				94A40C462B2781AF0028BC02 /* TransferPaymentOperation.swift */,
@@ -6207,6 +6210,7 @@
 				7C427BC428373F8000FFDE12 /* Wallpaper.swift in Sources */,
 				E090B90F23B0B27F0012C7E9 /* ConversationDAO+Search.swift in Sources */,
 				7BF42E3122DC85E9005066E6 /* GalleryImageItemViewController.swift in Sources */,
+				94F35A602D255B61001BCAE7 /* Invoice.swift in Sources */,
 				940764C529B26B0B00B779A6 /* PropertyListEncoder+Global.swift in Sources */,
 				7B8ED48021198EC20039946B /* StickerInputModelController.swift in Sources */,
 				94A0C8C32C77259E00BDE672 /* AddressReceiversCell.swift in Sources */,
diff --git a/Mixin/UserInterface/Controllers/Wallet/Payment/Invoice.swift b/Mixin/UserInterface/Controllers/Wallet/Payment/Invoice.swift
new file mode 100644
index 000000000..e72f432e9
--- /dev/null
+++ b/Mixin/UserInterface/Controllers/Wallet/Payment/Invoice.swift
@@ -0,0 +1,192 @@
+import Foundation
+import CryptoKit
+import MixinServices
+
+struct Invoice {
+    
+    enum Reference {
+        case hash(String)
+        case index(Int)
+    }
+    
+    struct Entry {
+        let traceID: String
+        let assetID: String
+        let amount: Decimal
+        let memo: String
+        let references: [Reference]
+    }
+    
+    let recipient: MIXAddress
+    let entries: [Entry]
+    
+}
+
+extension Invoice {
+    
+    private enum InitError: Error {
+        case invalidString
+        case base64Decoding
+        case invalidLength(Int)
+        case invalidChecksum
+        case unknownVersion
+        case invalidRecipient
+        case invalidEntriesCount
+        case invalidEntry
+        case invalidReferenceType
+        case invalidHashReference
+        case invalidIndexReference
+        case sha3
+    }
+    
+    private class DataReader {
+        
+        private let data: Data
+        
+        private var location: Data.Index
+        
+        init(data: Data) {
+            self.data = data
+            self.location = data.startIndex
+        }
+        
+        func readUInt8() -> UInt8? {
+            guard location != data.endIndex else {
+                return nil
+            }
+            let location = self.location
+            self.location = location.advanced(by: 1)
+            return data[location]
+        }
+        
+        func readUInt16() -> UInt16? {
+            let nextLocation = location.advanced(by: 2)
+            guard nextLocation <= data.endIndex else {
+                return nil
+            }
+            let low = data[location]
+            let high = data[location.advanced(by: 1)]
+            self.location = nextLocation
+            return UInt16(data: [low, high], endianess: .big)
+        }
+        
+        func readBytes(count: Int) -> Data? {
+            if count == 0 {
+                return Data()
+            }
+            let nextLocation = location.advanced(by: count)
+            guard nextLocation <= data.endIndex else {
+                return nil
+            }
+            let bytes = data[location..<nextLocation]
+            self.location = nextLocation
+            return bytes
+        }
+        
+        func readUUID() -> String? {
+            if let data = readBytes(count: UUID.dataCount) {
+                UUID(data: data).uuidString.lowercased()
+            } else {
+                nil
+            }
+        }
+        
+    }
+    
+    private static let version: UInt8 = 0
+    
+    init(string: String) throws {
+        let prefix = "MIN"
+        
+        guard string.hasPrefix(prefix) else {
+            throw InitError.invalidString
+        }
+        guard let data = Data(base64URLEncoded: string.suffix(string.count - prefix.count)) else {
+            throw InitError.base64Decoding
+        }
+        guard data.count >= 3 + 23 + 1 else {
+            throw InitError.invalidLength(data.count)
+        }
+        
+        let payload = data.prefix(data.count - 4)
+        let expectedChecksum = data.suffix(4)
+        let checksum = try {
+            let data = prefix.data(using: .utf8)! + payload
+            guard let digest = SHA3_256.hash(data: data) else {
+                throw InitError.sha3
+            }
+            return digest.prefix(4)
+        }()
+        guard expectedChecksum == checksum else {
+            throw InitError.invalidChecksum
+        }
+        
+        let reader = DataReader(data: payload)
+        guard reader.readUInt8() == Self.version else {
+            throw InitError.unknownVersion
+        }
+        
+        guard
+            let recipientLength = reader.readUInt16(),
+            let recipientData = reader.readBytes(count: Int(recipientLength)),
+            let recipient = MIXAddress(data: recipientData)
+        else {
+            throw InitError.invalidRecipient
+        }
+        
+        guard let entriesCount = reader.readUInt8() else {
+            throw InitError.invalidEntriesCount
+        }
+        var entries: [Entry] = []
+        entries.reserveCapacity(Int(entriesCount))
+        for _ in 0..<entriesCount {
+            guard
+                let traceID = reader.readUUID(),
+                let assetID = reader.readUUID(),
+                let amountLength = reader.readUInt8(),
+                let amountData = reader.readBytes(count: Int(amountLength)),
+                let amountString = String(data: amountData, encoding: .utf8),
+                let amount = Decimal(string: amountString, locale: .enUSPOSIX),
+                let extraLength = reader.readUInt16(),
+                let extra = reader.readBytes(count: Int(extraLength)),
+                let memo = String(data: extra, encoding: .utf8),
+                let referencesCount = reader.readUInt8()
+            else {
+                throw InitError.invalidEntry
+            }
+            
+            let references: [Reference] = try (0..<referencesCount).map { _ in
+                switch reader.readUInt8() {
+                case 0:
+                    if let hash = reader.readBytes(count: 32) {
+                        return .hash(hash.hexEncodedString())
+                    } else {
+                        throw InitError.invalidHashReference
+                    }
+                case 1:
+                    if let index = reader.readUInt8(), index < entries.count {
+                        return .index(Int(index))
+                    } else {
+                        throw InitError.invalidIndexReference
+                    }
+                default:
+                    throw InitError.invalidReferenceType
+                }
+            }
+            
+            let entry = Entry(
+                traceID: traceID,
+                assetID: assetID,
+                amount: amount,
+                memo: memo,
+                references: references
+            )
+            entries.append(entry)
+        }
+        
+        self.recipient = recipient
+        self.entries = entries
+    }
+    
+}
+
diff --git a/Mixin/UserInterface/Controllers/Wallet/Payment/MIXAddress.swift b/Mixin/UserInterface/Controllers/Wallet/Payment/MIXAddress.swift
index d18fa0358..207383f5f 100644
--- a/Mixin/UserInterface/Controllers/Wallet/Payment/MIXAddress.swift
+++ b/Mixin/UserInterface/Controllers/Wallet/Payment/MIXAddress.swift
@@ -11,7 +11,6 @@ enum MIXAddress {
     init?(string: String) {
         let header = "MIX"
         let headerData = header.data(using: .utf8)!
-        let version: UInt8 = 2
         
         guard string.hasPrefix(header) else {
             return nil
@@ -43,20 +42,25 @@ enum MIXAddress {
             return nil
         }
         
-        let payloadVersion: UInt8 = payload[0]
+        self.init(data: payload)
+    }
+    
+    init?(data payload: Data) {
+        let version: UInt8 = 2
+        let payloadVersion: UInt8 = payload[payload.startIndex]
         guard version == payloadVersion else {
             Logger.general.debug(category: "MIXAddress", message: "Unknown version")
             return nil
         }
         
-        let threshold: UInt8 = payload[1]
-        let membersCount: Int = Int(payload[2])
+        let threshold: UInt8 = payload[payload.startIndex.advanced(by: 1)]
+        let membersCount: Int = Int(payload[payload.startIndex.advanced(by: 2)])
         guard threshold != 0 && threshold <= membersCount && membersCount <= 64 else {
             Logger.general.debug(category: "MIXAddress", message: "Invalid threshold: \(threshold), total: \(membersCount)")
             return nil
         }
         
-        let membersData = payload[3...]
+        let membersData = payload[payload.startIndex.advanced(by: 3)...]
         switch membersData.count {
         case 16 * membersCount:
             let userIDs = (0..<membersCount).map { i in
diff --git a/MixinServices/MixinServices/Foundation/Extension/DataExtension.swift b/MixinServices/MixinServices/Foundation/Extension/DataExtension.swift
index 0425e5cd2..c1475e222 100644
--- a/MixinServices/MixinServices/Foundation/Extension/DataExtension.swift
+++ b/MixinServices/MixinServices/Foundation/Extension/DataExtension.swift
@@ -17,12 +17,13 @@ public extension Data {
         self.init(bytesNoCopy: bytes, count: count, deallocator: .free)
     }
     
-    init?(base64URLEncoded string: String) {
+    init?<S: StringProtocol>(base64URLEncoded string: S) {
         var str = string
             .replacingOccurrences(of: "-", with: "+")
             .replacingOccurrences(of: "_", with: "/")
-        if string.count % 4 != 0 {
-            str.append(String(repeating: "=", count: 4 - string.count % 4))
+        let remainder = string.count % 4
+        if remainder != 0 {
+            str.append(String(repeating: "=", count: 4 - remainder))
         }
         self.init(base64Encoded: str)
     }