Contra Costa County Property Tax Due Dates and How to Pay
Use this guide to check Contra Costa County property tax due dates and plan your payment. Confirm the current deadlines and payment details with the county before paying.
Contra Costa County property tax due dates at a glance
Contra Costa County property taxes are paid in two installments, according to the available search results [1]. For the first installment, the county’s Treasurer-Tax Collector calendar identifies December 10 as the last day to pay without penalty [2]. A separate search result says the first installment is due November 1 and becomes delinquent after December 10 [1]. Because the county calendar result provided here confirms the December 10 payment deadline but does not show the November 1 date, check your bill or the county calendar for the dates that apply to your property [2].
The first installment is due December 10 to avoid a penalty.[2] Before scheduling payment, use the county calendar or the dates printed on your property tax bill to verify the second installment date [2].
A practical way to read the information is to separate the first installment’s stated deadline from dates that still need confirmation: the county calendar excerpt gives December 10 as the last day to pay the first installment without penalty, while the November 1 date appears in a non-county search result [2][1]. If you are planning around a particular bill, confirm both installments directly against the calendar or bill rather than assuming the incomplete search result provides the full schedule [2][1].
When the first installment is due
When the first installment is due
For planning, keep two dates in view: November 1, when the first installment is reported as payable, and December 10, the county calendar’s last day to pay that installment without penalty. The November 1 payable date appears in nonofficial guides, so treat it as a reported date rather than a detail confirmed by the county calendar. [1][3] The county’s Treasurer-Tax Collector calendar identifies December 10 as the last day to pay the first installment without penalty. [2]
A practical way to use those dates is to put the payment on your calendar well before the final day. If you are organizing bills in October, note November 1 as the reported start of the payable period, then set a reminder ahead of December 10 so you have time to check your bill and payment arrangements. The sources establish the payable date and the county’s stated last day without penalty; they do not confirm a specific hour on December 10, so this section does not give a time-of-day cutoff. [2][1][3]
Before paying, confirm the installment and amount shown on your own tax bill, and use the county Treasurer-Tax Collector’s current payment information to choose a method. The available county calendar excerpt confirms the December 10 deadline, but it does not provide payment methods or processing details. [2] That distinction matters: a calendar date tells you the last day named for payment without penalty, but it does not establish how quickly a particular payment method will post. Check the county’s instructions rather than relying on an assumption about processing time.
In short, use November 1 as the reported payable date and December 10 as the county-listed last day to pay the first installment without penalty. [2][1][3] If you are close to the deadline, consult the county’s current guidance directly and avoid waiting until the last moment to resolve questions about your bill or payment.
Check the second installment deadline
Check the second installment deadline
Before paying, use your property tax bill and the county’s current Tax Collector calendar to confirm the second installment deadline. The county Treasurer-Tax Collector page lists a December 10 deadline for the first installment, but that information does not establish the second installment deadline. [2]
Start with the bill for the property you are paying. Check that it matches the property address or parcel information, then look for the second-installment amount and its due-date details. If the bill is not available, use the county’s tax lookup to find the account and installment options. Before submitting payment, confirm that the installment selected is the second one and review the amount shown for it. The lookup page notes that a service fee may be added to the taxes selected for payment, so review the payment total before completing the transaction. [4]
For example, if you have a bill in front of you but are unsure whether its deadline is current, compare the bill’s date information with the current county calendar rather than relying on a remembered date. If the bill and calendar appear inconsistent, check the account through the county lookup or contact the Treasurer-Tax Collector for clarification.
Keep a copy of the bill and the payment confirmation for your records. If you pay online, check the final total and selected installment before authorizing payment. These checks help you verify that you are paying the intended installment, without assuming a deadline that the available county information does not confirm.
How to check your bill and make a payment
- Open the Contra Costa County Treasurer-Tax Collector website and choose the tax lookup or account lookup option. The county’s tax lookup page provides an account lookup and installment options. [4] Use the account details shown there to locate the bill you want to review; if you have more than one property account, check each account separately so you do not confuse their bills.
- Review the installment amount and the due-date details displayed for the bill. The county Treasurer-Tax Collector calendar lists December 10 as the last day to pay the first installment without penalty. [2] Check the bill and current account information rather than relying on a date remembered from another bill or payment cycle. The lookup page also displays a current-date notice, so confirm the details available when you are preparing to pay. [4]
- Before submitting a payment, review the available payment options and any service fee. The county tax lookup page says a service fee is added in addition to the total amount of taxes selected for payment. [4] Check the amount shown on the payment screen before confirming, and make sure it matches the installment or installments you intend to pay. If the total includes a fee, account for that fee when deciding whether to continue.
- After payment, save the confirmation for your records. Keep it with your property-tax paperwork, and note which account and installment it relates to. That makes it easier to verify what you submitted if you later need to review your account. For example, a saved confirmation can help you distinguish a payment for one property from a payment for another; check the account information shown in the confirmation before filing it away.
If the lookup page does not show the bill or payment details you need, return to the county Treasurer-Tax Collector site and use its account lookup and installment options to check the account information again. [2][4]
Frequently asked questions
Where can I confirm the current due dates?
Check the Contra Costa County Treasurer-Tax Collector’s calendar for the county’s published installment information. The page identifies December 10 as the last day to pay the first installment without penalty. [2] Because a date on a page may not answer every question about your bill, confirm the details for your own property through the county’s tax lookup or directly with the Treasurer-Tax Collector. The tax lookup offers account lookup and installment options. [4]
For example, if you are checking a bill for a particular property, use the account lookup rather than relying only on a general calendar entry. This helps you review the installment information associated with that account. [4] If you cannot find the date or payment status you need, contact the county office using its current official contact information rather than guessing.
Does the December 10 date apply to the first installment?
Yes. The Treasurer-Tax Collector calendar describes December 10 as the last day to pay the first installment without penalty. [2] The wording is specifically about the first installment, so do not assume that it gives the due date for another installment. Check the county calendar and your account information for the details relevant to your bill. [2][4]
Where can I check payment options and service fees?
Use the county tax lookup to review account lookup and installment options. [4] The lookup page also says a service fee is added in addition to the total amount of taxes selected for payment. [4] Review the amount shown before submitting a payment so you can see the tax amount and any listed service fee. Check the current service fee on the payment screen before you submit your payment.
What if I need information beyond the calendar entry?
Start with the county’s Treasurer-Tax Collector page and tax lookup, then ask the county to clarify anything that is not clear for your account. The calendar entry establishes the first-installment date shown there, while the lookup page is where the county provides account lookup and installment options. [2][4] Avoid treating a general date as confirmation of a different installment’s deadline or of a payment’s status; check the account details directly.
Confirm the dates before you pay
Confirm the dates before you pay
For the first installment, Contra Costa County lists December 10 as the last day to pay without penalty. [2] Treat that as the county’s published cutoff, not as a substitute for checking the details on your own tax account. The official Tax Lookup tool offers account lookup and installment options, so use it to confirm which installment is due and what payment choices are available for your property. [4]
A practical approach is to check the account before you schedule or submit a payment. For example, if you are preparing to pay the first installment, compare the account information with the county’s December 10 cutoff. [2][4] If you are looking at the second installment, verify its due-date information directly through the county’s lookup tools rather than relying on a date from another property, an old notice, or an earlier year. The first installment is due December 10 to avoid a penalty.[2]
Use the account lookup to make sure you have selected the correct account and installment before proceeding. [4] The Tax Lookup page says a service fee may be added in addition to the total taxes selected for payment, so review the amount shown before completing a transaction. [4] This helps you distinguish the tax amount from any payment-related charge displayed by the tool.
In short: use December 10 as the published first-installment cutoff, then confirm the second installment and account-specific details through the official county tools before paying. [2][4] If the information on your account differs from what you expected, rely on the official account details and contact the Treasurer-Tax Collector through its county page for clarification. [2]