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Is it possible to send tokens to token holder? I have created my own ERC20 token and then send some tokens to user "B" now problem is when user "B" wants to send these tokens to user "A" token owner, I am getting this error in web3.eth.estimateGas():

Returned error: gas required exceeds allowance or always failing transaction

But user A(token owner) can send tokens to anyone easily.

Here is web3.js code:

module.exports.sendTokens = function(req, res){

    var toAddress = req.body.toAddress;
    var coins  = req.body.quantity;
    var fromAddress  = req.body.fromAddress;
    var privateKey  = req.body.fromAddressPvtKey;

    try{

        var contractAddress = contractConfig.contractAddress;
        var contractAbi = contractConfig.abiArray;

        //res.send({contractAddress:contractAddress, contractAbi:contractAbi});

        var myContract = new web3.eth.Contract(contractAbi, contractAddress);

        myContract.options.from = fromAddress;

        var transactionObject = {
            from: fromAddress,
            to: contractAddress,
            value: '0x00', 
            data: myContract.methods.transfer(toAddress, coins).encodeABI(),
            chainId: 3
        };

        web3.eth.estimateGas(transactionObject, function(err1, estimateGas){
            transactionObject.gasLimit = estimateGas;

            if(err1){
                res.send({error:true, errorMsg:err1.message, errorFunction:'estimateGas' });
            }

            web3.eth.accounts.signTransaction(transactionObject, privateKey , function(err2, signed){

                if(err2){
                    res.send({error:true, errorMsg:err2.message, errorFunction:'signTransaction'});
                }

                web3.eth.sendSignedTransaction(signed.rawTransaction, function(err3, txHash){

                    if(err3){
                        res.send({error:true, errorMsg:err3.message, errorFunction:'sendSignedTransaction'});
                    }

                    res.send({txHash:txHash});
                });

            });

        });

    }catch(err){
        res.send({error:true, errorMsg:err.message, errorFunction:'sendTokens' });
    }

}

Additional info:

Array
(
    [toAddress] => 0x45E6e1E13d3198701DbCbEE9134018b69011E9D2 // user A, token owner
    [quantity] => 200
    [fromAddress] => 0x45E6e1E13d3198701DbCbEE9134018b69011E9D2 // user B
    [fromAddressPvtKey] => 0xd4a9fc9bbbf647f257a1xxxxxxxxxxxxxxxx
)

From Address(user B, this user has enough tokens): https://ropsten.etherscan.io/address/0x45E6e1E13d3198701DbCbEE9134018b69011E9D2

To Address(real owner of tokens): https://ropsten.etherscan.io/address/0xf65881993013e9aa96a66f25628928aaff8e4317

Token Address: https://ropsten.etherscan.io/token/0xb74f749bc6954c2703773a4c1a9ba49bf754db77

Contract Address: https://ropsten.etherscan.io/address/0xb74f749bc6954c2703773a4c1a9ba49bf754db77 Contract:

contract BucksTecToken is ERC20Interface, Owned, SafeMath {
    string public symbol;
    string public  name;
    uint8 public decimals;
    uint public _totalSupply;

    mapping(address => uint) balances;
    mapping(address => mapping(address => uint)) allowed;


    // ------------------------------------------------------------------------
    // Constructor
    // ------------------------------------------------------------------------
    function BucksTecToken() public {
        symbol = "BucksTec";
        name = "Bucks Tec Token";
        decimals = 18;
        _totalSupply = 100000000000000000000000000;
        balances[0xf65881993013e9Aa96A66F25628928aAFF8E4317] = _totalSupply;
        Transfer(address(0), 0xf65881993013e9Aa96A66F25628928aAFF8E4317, _totalSupply);
    }


    // ------------------------------------------------------------------------
    // Total supply
    // ------------------------------------------------------------------------
    function totalSupply() public constant returns (uint) {
        return _totalSupply  - balances[address(0)];
    }


    // ------------------------------------------------------------------------
    // Get the token balance for account tokenOwner
    // ------------------------------------------------------------------------
    function balanceOf(address tokenOwner) public constant returns (uint balance) {
        return balances[tokenOwner];
    }


    // ------------------------------------------------------------------------
    // Transfer the balance from token owner's account to to account
    // - Owner's account must have sufficient balance to transfer
    // - 0 value transfers are allowed
    // ------------------------------------------------------------------------
    function transfer(address to, uint tokens) public returns (bool success) {
        balances[msg.sender] = safeSub(balances[msg.sender], tokens);
        balances[to] = safeAdd(balances[to], tokens);
        Transfer(msg.sender, to, tokens);
        return true;
    }


    // ------------------------------------------------------------------------
    // Token owner can approve for spender to transferFrom(...) tokens
    // from the token owner's account
    //
    // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
    // recommends that there are no checks for the approval double-spend attack
    // as this should be implemented in user interfaces 
    // ------------------------------------------------------------------------
    function approve(address spender, uint tokens) public returns (bool success) {
        allowed[msg.sender][spender] = tokens;
        Approval(msg.sender, spender, tokens);
        return true;
    }


    // ------------------------------------------------------------------------
    // Transfer tokens from the from account to the to account
    // 
    // The calling account must already have sufficient tokens approve(...)-d
    // for spending from the from account and
    // - From account must have sufficient balance to transfer
    // - Spender must have sufficient allowance to transfer
    // - 0 value transfers are allowed
    // ------------------------------------------------------------------------
    function transferFrom(address from, address to, uint tokens) public returns (bool success) {
        balances[from] = safeSub(balances[from], tokens);
        allowed[from][msg.sender] = safeSub(allowed[from][msg.sender], tokens);
        balances[to] = safeAdd(balances[to], tokens);
        Transfer(from, to, tokens);
        return true;
    }


    // ------------------------------------------------------------------------
    // Returns the amount of tokens approved by the owner that can be
    // transferred to the spender's account
    // ------------------------------------------------------------------------
    function allowance(address tokenOwner, address spender) public constant returns (uint remaining) {
        return allowed[tokenOwner][spender];
    }


    // ------------------------------------------------------------------------
    // Token owner can approve for spender to transferFrom(...) tokens
    // from the token owner's account. The spender contract function
    // receiveApproval(...) is then executed
    // ------------------------------------------------------------------------
    function approveAndCall(address spender, uint tokens, bytes data) public returns (bool success) {
        allowed[msg.sender][spender] = tokens;
        Approval(msg.sender, spender, tokens);
        ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, this, data);
        return true;
    }


    // ------------------------------------------------------------------------
    // Don't accept ETH
    // ------------------------------------------------------------------------
    function () public payable {
        revert();
    }


    // ------------------------------------------------------------------------
    // Owner can transfer out any accidentally sent ERC20 tokens
    // ------------------------------------------------------------------------
    function transferAnyERC20Token(address tokenAddress, uint tokens) public onlyOwner returns (bool success) {
        return ERC20Interface(tokenAddress).transfer(owner, tokens);
    }
}
  • There are a lot of possibilities: perhaps contractAddress is wrong, or toAddress is wrong, or fromAddress doesn't have a balance of at least coins... there's not enough information here for someone else to debug your transaction. – user19510 May 12 '18 at 15:20
  • @smarx I have updated the answer, pls have a look. – Muhammad Shahzad May 12 '18 at 17:12

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