If you are unable to withdraw your funds — such as US Dollar (USD), Bitcoin (BTC), Ethereum (ETH), Euro (EUR), or Canadian Dollars (CAD) — there may be several reasons for this.

You may see a "Balance is insufficient for a withdrawal" error, or the withdrawal page may say that your funds are "Withheld" or that withdrawals are blocked.

Check the following:

Recent Fiat Deposits

Have you recently deposited fiat for the first time? This will result in any withdrawals on your account up to 100% of the deposit amount being blocked.

Solution: try to withdraw a smaller amount or wait 72 hours.

Open/pending orders

Do you have any orders open/pending? Fiat currency that is used in an open/pending order cannot be withdrawn.

Solution: cancel the open orders.

Open spot positions on margin 

Do you have any open spot positions on margin?  Spot positions on margin require collateral, and that collateral cannot be withdrawn while the positions are open.

Solution: close the open spot positions on margin.

Negative balance

Do you have a negative balance in any currency? This will prevent withdrawals from your account.

Solution: deposit funds in the currency that has a negative balance, or exchange other currencies to make up for the negative balance. 

Currency not held in your account

Do you have the currency available in your Kraken account? Although you may see the total amount held in your account, you may have it selected where your account shows the total sum of all of your currencies shown in a specific currency, though all of your currencies held are treated separately.

An example is if you hold both Great British Pounds (GBP) and eurozone euros (EUR)  in your account, you can't withdraw the total amount in one US Dollars (USD) withdrawal.

Solution: exchange your balances to the currency you want to withdraw.