This is how the IRS gets your immediate attention when you have ignored their previous letters.
A levy is delivered to your bank instructing them to withdraw ALL money in ALL accounts held at that bank which your tax identification number listed as an authorized signer. The tax identification number is your social security number (SSN) if it is personal tax debt or your employer identification number (EIN) if it is business tax debt.
You may have been added as a signer to an account you do not normally use such as one primarily used by your spouse, kid, parent, sibling or friend. The IRS doesn’t care about your agreement with another person on the account. If you tax identification number is associated with an account, it will be wiped clean by the bank.
To add insult to injury, your checks will bounce, the bank may charge you a processing fee and if the tax debt is not paid off this time, the IRS will mail another levy to your bank in the future.