diff --git a/packages/ilp-packet/index.ts b/packages/ilp-packet/index.ts
index 265321b7..465d16f9 100644
--- a/packages/ilp-packet/index.ts
+++ b/packages/ilp-packet/index.ts
@@ -9,6 +9,8 @@ import { stringToTwoNumbers, twoNumbersToString } from './src/utils/uint64'
 import Long = require('long')
 import * as assert from 'assert'
 
+export const Errors = require('./src/errors')
+
 export enum Type {
   TYPE_ILP_PAYMENT = 1,
   TYPE_ILQP_LIQUIDITY_REQUEST = 2,
@@ -26,6 +28,21 @@ export enum Type {
   TYPE_ILP_REJECT = 14
 }
 
+export interface IlpErrorClass {
+  message: string,
+  ilpErrorCode?: string,
+  ilpData?: Buffer
+}
+
+export const errorToReject = (address: string, error: IlpErrorClass) => {
+  return serializeIlpReject({
+    code: error.ilpErrorCode || 'F00',
+    triggeredBy: address,
+    message: error.message || '',
+    data: error.ilpData || Buffer.alloc(0)
+  })
+}
+
 export const serializeEnvelope = (type: number, contents: Buffer) => {
   const writer = new Writer()
   writer.writeUInt8(type)
diff --git a/packages/ilp-packet/src/errors.ts b/packages/ilp-packet/src/errors.ts
new file mode 100644
index 00000000..0e82c6f7
--- /dev/null
+++ b/packages/ilp-packet/src/errors.ts
@@ -0,0 +1,213 @@
+import { Writer } from 'oer-utils'
+import { stringToTwoNumbers, twoNumbersToString } from './utils/uint64'
+import BaseError = require('extensible-error')
+
+export const codes = {
+  F00_BAD_REQUEST: 'F00',
+  F01_INVALID_PACKET: 'F01',
+  F02_UNREACHABLE: 'F02',
+  F03_INVALID_AMOUNT: 'F03',
+  F04_INSUFFICIENT_DESTINATION_AMOUNT: 'F04',
+  F05_WRONG_CONDITION: 'F05',
+  F06_UNEXPECTED_PAYMENT: 'F06',
+  F07_CANNOT_RECEIVE: 'F07',
+  F08_AMOUNT_TOO_LARGE: 'F08',
+  F99_APPLICATION_ERROR: 'F99',
+  T00_INTERNAL_ERROR: 'T00',
+  T01_PEER_UNREACHABLE: 'T01',
+  T02_PEER_BUSY: 'T02',
+  T03_CONNECTOR_BUSY: 'T03',
+  T04_INSUFFICIENT_LIQUIDITY: 'T04',
+  T05_RATE_LIMITED: 'T05',
+  T99_APPLICATION_ERROR: 'T99',
+  R00_TRANSFER_TIMED_OUT: 'R00',
+  R01_INSUFFICIENT_SOURCE_AMOUNT: 'R01',
+  R02_INSUFFICIENT_TIMEOUT: 'R02',
+  R99_APPLICATION_ERROR: 'R99'
+}
+
+export class BadRequestError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.F00_BAD_REQUEST
+  }
+}
+
+export class InvalidPacketError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.F01_INVALID_PACKET
+  }
+}
+
+export class UnreachableError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.F02_UNREACHABLE
+  }
+}
+
+export class InvalidAmountError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.F03_INVALID_AMOUNT
+  }
+}
+
+export class InsufficientDestinationAmountError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.F04_INSUFFICIENT_DESTINATION_AMOUNT
+  }
+}
+
+export class WrongConditionError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.F05_WRONG_CONDITION
+  }
+}
+
+export class UnexpectedPaymentError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.F06_UNEXPECTED_PAYMENT
+  }
+}
+
+export class CannotReceiveError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.F07_CANNOT_RECEIVE
+  }
+}
+
+export interface AmountTooLargeErrorOpts {
+  receivedAmount: string,
+  maximumAmount: string
+}
+
+export class AmountTooLargeError extends BaseError {
+  public ilpErrorCode: string
+  public ilpData: Buffer
+  constructor (message: string, opts: AmountTooLargeErrorOpts) {
+    super(message)
+    this.ilpErrorCode = codes.F08_AMOUNT_TOO_LARGE
+
+    const writer = new Writer()
+    writer.writeUInt64(stringToTwoNumbers(opts.receivedAmount))
+    writer.writeUInt64(stringToTwoNumbers(opts.maximumAmount))
+
+    this.ilpData = writer.getBuffer()
+  }
+}
+
+export class FinalApplicationError extends BaseError {
+  public ilpErrorCode: string
+  public ilpData: Buffer
+  constructor (message: string, data: Buffer) {
+    super(message)
+    this.ilpErrorCode = codes.F99_APPLICATION_ERROR
+    this.ilpData = data
+  }
+}
+
+export class InternalError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.T00_INTERNAL_ERROR
+  }
+}
+
+export class PeerUnreachableError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.T01_PEER_UNREACHABLE
+  }
+}
+
+export class PeerBusyError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.T02_PEER_BUSY
+  }
+}
+
+export class ConnectorBusyError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.T03_CONNECTOR_BUSY
+  }
+}
+
+export class InsufficientLiquidityError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.T04_INSUFFICIENT_LIQUIDITY
+  }
+}
+
+export class RateLimitedError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.T05_RATE_LIMITED
+  }
+}
+
+export class TemporaryApplicationError extends BaseError {
+  public ilpErrorCode: string
+  public ilpData: Buffer
+  constructor (message: string, data: Buffer) {
+    super(message)
+    this.ilpErrorCode = codes.T99_APPLICATION_ERROR
+    this.ilpData = data
+  }
+}
+
+export class TransferTimedOutError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.R00_TRANSFER_TIMED_OUT
+  }
+}
+
+export class InsufficientSourceAmountError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.R01_INSUFFICIENT_SOURCE_AMOUNT
+  }
+}
+
+export class InsufficientTimeoutError extends BaseError {
+  public ilpErrorCode: string
+  constructor (message: string) {
+    super(message)
+    this.ilpErrorCode = codes.R02_INSUFFICIENT_TIMEOUT
+  }
+}
+
+export class RelativeApplicationError extends BaseError {
+  public ilpErrorCode: string
+  public ilpData: Buffer
+  constructor (message: string, data: Buffer) {
+    super(message)
+    this.ilpErrorCode = codes.R99_APPLICATION_ERROR
+    this.ilpData = data
+  }
+}