Buying in Bellevue and trying to make sense of King County property taxes? You are not alone. Taxes affect your monthly payment, your closing costs, and your budget in year one. In this guide, you will learn how values are set, what makes up the tax rate, how bills and escrow work, and how to estimate your monthly impact, including potential supplemental bills after you buy. Let’s dive in.
How King County values homes
King County assesses every property each year to estimate market value as of January 1. Notices usually arrive in late spring and reflect the county’s opinion of fair value for that date. You should review the assessed value for the home you want to buy so you understand what the county currently shows and how it has changed.
If the assessed value looks off once you own the home, you can appeal. Appeals have firm deadlines, so act quickly if you plan to challenge a valuation. Check the King County Department of Assessments for current timelines and instructions.
What makes up your tax rate
Property taxes equal assessed value multiplied by the combined levy rate for your parcel. In Washington, levy rates are expressed as dollars per $1,000 of assessed value. Your total rate is the sum of all applicable districts for your property.
Typical Bellevue districts include the City of Bellevue, King County, Bellevue School District, King County Library System, Eastside Fire & Rescue, Sound Transit, and sometimes other special-purpose districts. Some portions of the bill are voter-approved and can change when new measures pass. To see the exact districts and rates for a specific home, use King County’s parcel tools to view the levy summary and combined rate.
Find your parcel’s numbers
Use the King County Assessor parcel search to look up the property by address or parcel number. Note the current assessed value and the assessment year. Then review the parcel’s levy summary, which lists each district and the combined rate per $1,000.
Write down two items before you estimate your payment:
- Assessed value for the current year.
- Combined levy rate for the parcel.
These two numbers drive your annual tax and your monthly escrow estimate.
Estimate your annual and monthly cost
Use this simple formula:
- Annual tax = (Assessed value ÷ 1,000) × Combined levy rate.
- Estimated monthly escrow = Annual tax ÷ 12, plus any lender-required cushion.
Example for illustration only:
- If the assessed value is $900,000 and the combined levy rate is $12.00 per $1,000:
- Annual tax = (900,000 ÷ 1,000) × 12.00 = $10,800.
- Monthly escrow ≈ $900, plus any lender cushion.
Because rates and assessments can change, repeat this estimate once you have the latest parcel data and your lender’s escrow breakdown.
Due dates, billing, and escrow
King County bills property taxes in two installments each year. Many owners pay through a mortgage escrow account that sets aside funds monthly for the upcoming bills. Check the King County Treasurer for current due dates and payment options.
If you finance your purchase, your lender will likely set up an escrow account for taxes and homeowners insurance. Your monthly mortgage payment will include principal, interest, and your escrow deposit for taxes and insurance. At closing, most lenders collect an initial escrow deposit to fund upcoming payments and maintain a small reserve. The exact amount depends on your closing date and the next tax due date, so ask your lender and escrow officer for a written estimate.
How tax proration works at closing
Taxes are usually prorated between buyer and seller based on the closing date. Each party pays for the days they owned the property. The closing statement will show how proration was calculated, typically using the most recent known tax amount.
Review your closing disclosure and ask the escrow officer to explain the figures. Confirm whether any prior-year amounts are due and how your lender will handle the first upcoming tax installment.
Supplemental assessments after you buy
A change in ownership or certain improvements can trigger a supplemental assessment. This is a valuation that adjusts the property’s value as of the date of your purchase or improvement and can lead to an additional, prorated tax bill for the remainder of the year. Supplemental bills are separate from the regular first and second half bills.
Timing varies. The assessor processes the transfer, then the treasurer issues the supplemental bill, often weeks to a few months after closing. Some lenders do not escrow supplemental bills. You may receive the bill directly, so plan ahead.
Here is a simple way to estimate a potential supplemental bill:
- Find the prior assessed value on the parcel record.
- Use the sale price as a rough proxy for the new value if the supplemental notice is not yet available.
- Calculate the incremental value: new value minus prior assessed value.
- Supplemental annual tax ≈ (Incremental value ÷ 1,000) × Combined levy rate.
- Prorate it: Supplemental bill ≈ Supplemental annual tax × (months remaining in the year ÷ 12).
This is only an estimate. The assessor’s supplemental value can differ from the sale price.
Bellevue districts to watch
Several local districts commonly make up a large share of Bellevue tax bills:
- Bellevue School District for operating levies and bonds.
- City of Bellevue general levies.
- King County levies for county services.
- King County Library System.
- Eastside Fire & Rescue.
- Sound Transit for regional transit measures.
- Other special purpose districts as applicable to the parcel.
Use the parcel’s levy summary to see your exact mix and to track any voter-approved measures.
Smart buyer checklist
Before you write an offer:
- Look up the current assessed value and levy summary for the property.
- Ask the listing agent for the most recent annual tax amount and whether any improvements might trigger a supplemental bill.
During escrow:
- Confirm how taxes will be prorated on your settlement statement.
- Ask your lender for a written breakdown of the monthly escrow amount and the initial escrow deposit.
- Clarify whether your lender will handle any supplemental bill triggered by the purchase.
After closing:
- Watch for the assessor’s notice of supplemental value and any supplemental tax bill.
- Verify with your lender if the supplemental bill will be paid from escrow or if you should pay it directly.
Budgeting tips:
- Base your monthly estimate on the parcel’s assessed value and combined rate, not a generic average.
- Add a cushion for potential supplemental taxes in year one and for possible levy changes year to year.
- Revisit your budget when you receive updated assessments or when voters approve new measures.
Local resources to use
- King County Department of Assessments for parcel values, notices, and appeal instructions.
- King County Treasurer for bills, due dates, and payment options.
- City of Bellevue for municipal tax context.
- Bellevue School District for levy and bond information.
- Sound Transit and other local districts for voter-approved measures.
- Washington State Department of Revenue for statewide property tax rules.
Ready for a personalized estimate?
If you are buying in Bellevue, a clear tax plan can make your first year smoother. Bring the parcel record, assessed value, levy summary, and your lender’s escrow estimate. We will walk through your numbers, highlight potential supplemental charges, and help you budget with confidence. Contact Yang Xiao for a personalized review of your property’s taxes, escrow impacts, and closing costs.
FAQs
How do I estimate Bellevue property taxes?
- Use the formula: (Assessed value ÷ 1,000) × Combined levy rate for the parcel, which you can find on King County’s parcel tools.
Will my lender escrow a supplemental tax bill after purchase?
- Not always; many lenders do not include supplemental bills in escrow, so ask your lender before closing how these will be handled.
When will I get my first tax bill after I buy?
- Regular bills follow the county’s annual schedule, while any supplemental bill is typically issued weeks to a few months after the transfer is recorded.
Can I appeal a big jump in assessed value?
- Yes; King County allows appeals, but deadlines are strict, so review your notice and contact the assessor right away if you plan to challenge it.
Do Bellevue property taxes fund local schools?
- Yes; a portion of your bill supports the Bellevue School District through regular and voter-approved levies and bonds.