diff --git a/src/logic/safe/safeTxSigner.js b/src/logic/safe/safeTxSigner.js
new file mode 100644
index 00000000..d6b0b92d
--- /dev/null
+++ b/src/logic/safe/safeTxSigner.js
@@ -0,0 +1,161 @@
+// @flow
+import { getWeb3 } from '~/logic/wallets/getWeb3'
+import { promisify } from '~/utils/promisify'
+import { BigNumber } from 'bignumber.js'
+import { EMPTY_DATA } from '~/logic/wallets/ethTransactions'
+import { getSignaturesFrom } from '~/utils/localStorage/signatures'
+
+const estimateDataGasCosts = (data) => {
+  const reducer = (accumulator, currentValue) => {
+    if (currentValue === EMPTY_DATA) {
+      return accumulator + 0
+    }
+
+    if (currentValue === '00') {
+      return accumulator + 4
+    }
+
+    return accumulator + 68
+  }
+
+  return data.match(/.{2}/g).reduce(reducer, 0)
+}
+
+
+export const estimateDataGas = (
+  safe: any,
+  to: string,
+  valueInWei: number,
+  data: string,
+  operation: number,
+  txGasEstimate: number,
+  gasToken: number,
+  nonce: number,
+  signatureCount: number,
+) => {
+  // numbers < 256 are 192 -> 31 * 4 + 68
+  // numbers < 65k are 256 -> 30 * 4 + 2 * 68
+  // For signature array length and dataGasEstimate we already calculated
+  // the 0 bytes so we just add 64 for each non-zero byte
+  const gasPrice = 0 // no need to get refund when we submit txs to metamask
+  const signatureCost = signatureCount * (68 + 2176 + 2176) // array count (3 -> r, s, v) * signature count
+
+  const sigs = getSignaturesFrom(safe.address, nonce)
+  const payload = safe.contract.execTransactionAndPaySubmitter
+    .getData(to, valueInWei, data, operation, txGasEstimate, 0, gasPrice, gasToken, sigs)
+
+  let dataGasEstimate = estimateDataGasCosts(payload) + signatureCost
+  if (dataGasEstimate > 65536) {
+    dataGasEstimate += 64
+  } else {
+    dataGasEstimate += 128
+  }
+  return dataGasEstimate + 34000 // Add aditional gas costs (e.g. base tx costs, transfer costs)
+}
+
+// eslint-disable-next-line
+export const generateTxGasEstimateFrom = async (
+  safe: any,
+  safeAddress: string,
+  data: string,
+  to: string,
+  valueInWei: number,
+  operation: number,
+) => {
+  try {
+    const estimateData = safe.contract.requiredTxGas.getData(to, valueInWei, data, operation)
+    const estimateResponse = await promisify(cb => getWeb3().eth.call({
+      to: safeAddress,
+      from: safeAddress,
+      data: estimateData,
+    }, cb))
+    const txGasEstimate = new BigNumber(estimateResponse.substring(138), 16)
+
+    // Add 10k else we will fail in case of nested calls
+    return Promise.resolve(txGasEstimate.toNumber() + 10000)
+  } catch (error) {
+    // eslint-disable-next-line
+    console.log("Error calculating tx gas estimation " + error)
+    return Promise.resolve(0)
+  }
+}
+
+const generateTypedDataFrom = async (
+  safe: any,
+  safeAddress: string,
+  to: string,
+  valueInWei: number,
+  nonce: number,
+  data: string,
+  operation: number,
+  txGasEstimate: number,
+) => {
+  const txGasToken = 0
+  // const threshold = await safe.getThreshold()
+  // estimateDataGas(safe, to, valueInWei, data, operation, txGasEstimate, txGasToken, nonce, threshold)
+  const dataGasEstimate = 0
+  const gasPrice = 0
+  const typedData = {
+    types: {
+      EIP712Domain: [
+        {
+          type: 'address',
+          name: 'verifyingContract',
+        },
+      ],
+      PersonalSafeTx: [
+        { type: 'address', name: 'to' },
+        { type: 'uint256', name: 'value' },
+        { type: 'bytes', name: 'data' },
+        { type: 'uint8', name: 'operation' },
+        { type: 'uint256', name: 'safeTxGas' },
+        { type: 'uint256', name: 'dataGas' },
+        { type: 'uint256', name: 'gasPrice' },
+        { type: 'address', name: 'gasToken' },
+        { type: 'uint256', name: 'nonce' },
+      ],
+    },
+    domain: {
+      verifyingContract: safeAddress,
+    },
+    primaryType: 'PersonalSafeTx',
+    message: {
+      to,
+      value: valueInWei,
+      data,
+      operation,
+      safeTxGas: txGasEstimate,
+      dataGas: dataGasEstimate,
+      gasPrice,
+      gasToken: txGasToken,
+      nonce,
+    },
+  }
+
+  return typedData
+}
+
+export const generateMetamaskSignature = async (
+  safe: any,
+  safeAddress: string,
+  sender: string,
+  to: string,
+  valueInWei: number,
+  nonce: number,
+  data: string,
+  operation: number,
+  txGasEstimate: number,
+) => {
+  const web3 = getWeb3()
+  const typedData =
+    await generateTypedDataFrom(safe, safeAddress, to, valueInWei, nonce, data, operation, txGasEstimate)
+  const signedTypedData = {
+    jsonrpc: '2.0',
+    method: 'eth_signTypedData',
+    params: [sender, typedData],
+    id: Date.now(),
+  }
+  const txSignedResponse = await promisify(cb => web3.currentProvider.sendAsync(signedTypedData, cb))
+
+  return txSignedResponse.result.replace(EMPTY_DATA, '')
+}