California FTB Notice Notice of State Income Tax Due (FTB 4963)

FTB 4963 is California’s standard demand notice telling you that you owe state income tax. It’s not an audit notice — FTB isn’t questioning your return. It’s a billing notice for a balance that FTB says is already established on your account, whether from a filed return with a balance due, a prior assessment, or an unpaid prior-year liability.

The notice shows the principal tax, penalties, and interest outstanding. The interest figure will be current through the notice date, but it’s accruing daily — by the time you receive the notice in the mail, the actual amount owed is already slightly higher. Don’t pay the exact amount on the notice without calling FTB for a current payoff figure.

Act within 30 days. FTB 4963 is a demand for payment. If you don’t respond — by paying, setting up a payment plan, or disputing the balance — FTB will escalate to more aggressive collection: liens, levies, wage garnishments.

Yes, but the dispute process depends on what the balance represents. If FTB 4963 reflects a balance from your own filed return that you now believe is incorrect, you need to file an amended California return (Form 540X) along with a written explanation of the change. The amended return and protest don’t go to the same place — the amended return goes to FTB’s Returns Processing division and the dispute letter goes to Collections or the Protest Unit depending on where the balance is in the collection cycle.

If the balance on FTB 4963 reflects a prior assessment you never agreed with — from an audit or a proposed assessment — and the protest window has closed, your administrative options are limited. You can still request an informal review by FTB’s Taxpayer Rights Advocate office, or you can pay the balance under protest and sue for a refund in California Superior Court under Revenue and Taxation Code Section 19382.

If the balance appears to be based on erroneous information — a payment that wasn’t credited, a return that wasn’t processed, or someone else’s liability on your account — document it thoroughly and contact FTB’s Collections division directly. These are fixable problems but they require paperwork and follow-up.

California charges interest on unpaid income tax at the federal short-term rate (set quarterly) plus 3 percentage points, compounding daily. For 2024 and 2025, that has run between 8% and 11% annualized depending on the quarter. Unlike some states that fix the interest rate, California’s rate floats with federal rates.

On top of interest, the failure-to-pay penalty is 5% of the unpaid tax on the first month, then 0.5% per month for each additional month unpaid, up to a maximum of 25% of the original tax owed. If you also failed to file a return, the failure-to-file penalty is 5% per month up to 25% — and both penalties can apply simultaneously, though the combined cap limits the total penalty to 25% from the failure-to-file and an additional 0.5% per month from failure-to-pay.

One important distinction: if you had an installment agreement in place and defaulted, a reinstatement fee applies alongside resumed penalty accrual. Getting back into good standing costs more than staying current. That’s why we push clients to contact FTB before missing a payment rather than after.

Yes — and if you can’t pay the full balance, an installment agreement is almost always the right move after receiving FTB 4963. California allows installment agreements for most tax debts. For balances under $25,000, you can apply online through MyFTB. For balances over $25,000, you’ll need to submit Form FTB 3567 along with a completed Collection Information Statement (Form FTB 3561).

FTB generally requires that the installment agreement pays off the full balance within 60 months. On a $12,000 balance, that’s $200/month minimum — though the actual required payment will be higher once you factor in the interest still accruing. A common mistake is setting up a $200/month plan on a $12,000 balance without realizing that interest at 7% annually will add roughly $70/month to the balance, meaning the plan barely keeps pace unless the monthly payment is larger.

We help clients calculate the real payoff amount needed to make meaningful progress on the balance, not just stay even with interest. Getting the installment payment right the first time prevents the unpleasant surprise of finishing the 60-month plan and still owing money because interest outpaced payments.

FTB 4963 notices are sometimes generated before a payment fully posts to your account. California’s FTB systems can take two to six weeks to match an incoming payment to the correct account and tax year — especially if you mailed a check or paid through a third-party service. A notice triggered before your payment cleared will still show the full balance.

Don’t ignore the notice assuming it will sort itself out. Gather proof of your payment — bank statement showing the cleared check, confirmation number from an online payment, or a certified mail receipt — and call FTB at 800-852-5711. Reference your account number and the 4963 notice number. Ask them to confirm the payment posted and verify your current balance. If payment hasn’t posted yet, ask when it will and note the agent’s name and ID.

If you paid and the money never actually cleared — wrong account number, check lost in mail — you’ll need to trace the payment and make a new one while showing FTB proof of your attempt to pay. Banks can issue a stop payment on a lost check and provide documentation of the original transaction. Keep copies of everything until FTB confirms a zero balance in writing.