Welcome to IXIDE — your partner in the world of cryptocurrency!

In the “IXIDE Explains” series, we break down crypto terms and situations in simple language.

Today, we’ll explain what a mempool is, why a transaction can remain unconfirmed for a long time, and what to do if the transfer has already been sent, a TXID exists, but the funds have not yet been credited.

What Is a Mempool?

A mempool is a temporary queue of transactions that have already been broadcast to the blockchain but have not yet been included in a block.

In simple terms:

wallet sends a transaction → it enters the mempool → a miner or validator includes it in a block → the first confirmation appears.

While a transaction remains in the mempool, it is considered unconfirmed.

Why Is This Queue Needed?

A blockchain cannot include every new transaction in a single block at the same time.

If users create more transactions than the network can process within a short period, some of them have to wait.

That is what the mempool is for.

The term is especially common when talking about Bitcoin.

Why Can a Transaction Get “Stuck”?

One of the most common reasons is high network congestion.

If many users are sending transactions at the same time, the mempool grows.

Bitcoin miners then decide which transactions to include in the next block.

Transactions offering a more attractive fee relative to their size usually receive higher priority.

As a result, a transaction with a low fee may remain unconfirmed for much longer.

Why Does the Fee Affect Speed?

Imagine two Bitcoin transactions are sent at almost the same time.

The first has a fee that matches current network conditions.

The second has a much lower fee.

The first may be included in the next block, while the second may continue waiting in the mempool.

So even two transactions sent at nearly the same time can be confirmed at very different speeds.

What Do Pending or Unconfirmed Mean?

If a blockchain explorer shows the status:

Pending

or

Unconfirmed,

it usually means the network has already seen the transaction, but it has not yet been included in a block.

Once it is included, the first confirmation appears.

After that, the number of confirmations increases as new blocks are added.

Why Is There Already a TXID if the Transfer Is Not Complete?

A TXID is created before a transaction receives confirmation.

So the presence of a TXID means the transaction has already been formed and broadcast to the network.

But it does not mean the blockchain has fully processed it yet.

The receiving service may wait for:

the first confirmation;
several confirmations;
additional internal processing.

That is why some time may pass between the appearance of a TXID and the actual crediting of funds.

Can a Stuck Transaction Be Accelerated?

Sometimes, yes.

In Bitcoin, one of the mechanisms used for this is Replace-by-Fee, or RBF.

If the original transaction was created with RBF support, the wallet may allow the user to replace it with a new version that has a higher fee.

This gives miners a stronger incentive to include the updated transaction in a block.

However, not every wallet supports this feature, and it depends on how the original transaction was created.

What Is CPFP?

Another mechanism is Child Pays for Parent, or CPFP.

It can be used with linked transactions, where a new transaction pays a higher fee and makes it more attractive for a miner to confirm both transactions together.

This is a more technical method and is usually handled by the wallet or specialized tools rather than manually by an ordinary user.

Should You Increase the Fee Immediately?

Not always.

If the transfer is not urgent, sometimes the best option is simply to wait.

Network congestion may decrease, and the transaction may be confirmed without any additional action.

Before trying to accelerate it, check:

the transaction status;
current network congestion;
the fee;
the features supported by your wallet.

Can a Transaction Disappear From the Mempool?

If a transaction remains unconfirmed for a very long time, some nodes may eventually stop keeping it in their mempool.

This does not automatically mean the funds are lost.

Depending on the network and wallet, the transaction may be rebroadcast, or the funds may become available for a new transaction.

In such a case, it is better to rely on blockchain explorer data and the options provided by the wallet you are using.

Does Mempool Exist Only in Bitcoin?

No, but different blockchains handle pending transactions in different ways.

The term mempool is especially common in Bitcoin.

Ethereum, TRON, and other networks also have their own mechanisms for processing pending transactions, but their fee models, prioritization rules, and block inclusion logic may differ.

That is why Bitcoin mempool behavior should not be applied directly to every other blockchain.

What Does This Mean for IXIDE Users?

When exchanging through IXIDE, a user may encounter a situation where the cryptocurrency has already been sent and a TXID exists, but the order is still waiting.

This does not always mean there is a delay on the exchanger’s side.

If the transaction has not yet received the required number of confirmations, the service has to wait for the blockchain network to process it.

The user can independently check the TXID and review:

the transaction status;
the number of confirmations;
the amount;
the recipient address;
the current state of the transaction on the network.

Once the blockchain provides the required number of confirmations, the order can move to the next stage of processing.

What Should You Do if a Transaction Is Taking Too Long?

First, open the transaction in a blockchain explorer using the TXID.

Check:

whether the transaction exists;
its current status;
the number of confirmations;
the fee;
whether the recipient address is correct;
whether the amount is correct.

If the transaction is still unconfirmed, check whether your wallet supports fee adjustment.

If you are unsure what is happening, you can contact IXIDE support and provide:

the order number;
TXID;
cryptocurrency;
network;
amount.

This makes it easier to determine whether the transaction is still waiting on the blockchain side or has already moved to the next processing stage.

What You Should Not Do

If a transaction is taking a long time to confirm, do not immediately send the same amount again.

You also should not provide anyone with:

your seed phrase;
private key;
wallet login credentials.

For checking the status of a transaction, the TXID is usually enough.

Be especially careful with websites or individuals promising to “instantly accelerate” a transaction in exchange for your seed phrase or private key.

IXIDE Recommends

Before sending cryptocurrency, always check:

the recipient address;
the network;
the amount;
the recommended fee;
current network conditions.

If a TXID already exists but there are still no confirmations, do not immediately assume the transfer is lost.

First, check its actual status on the blockchain.

IXIDE recommends relying on blockchain explorer data and the current network status rather than only on the number of minutes that have passed since the transaction was sent.

Key Takeaway

A mempool is a queue of unconfirmed transactions.

A transaction can be delayed because of:

high network congestion;
a low fee;
the specific rules of the blockchain being used.

Having a TXID does not yet mean the transaction has been confirmed.

If a transfer is delayed, first check it in a blockchain explorer. Only after that should you decide whether to wait, increase the fee, or contact support.

For IXIDE users, the main rule is simple: do not resend funds before checking the transaction, and keep the TXID until the exchange is fully completed.

IXIDE Explains: What Is a Mempool and Why Can a Transaction Get Stuck?