🏦 什麼是 Escrow Impound？為什麼保費變動會讓你的房貸月供（Mortgage Payment）增加？
很多加州房主第一次遇到房東說「你的 impound 不夠，需要補錢」時，都會嚇一跳。尤其最近房屋保險全面上漲，加上 surcharge（附加費），很多房主突然收到貸款銀行的通知，月供金額跳高了。
別擔心，本篇會用最簡單的方式解釋 Impound 是什麼、它怎麼計算，以及為什麼保費變動會直接影響你的 Mortgage Payment。
📌 1. Escrow Impound 是什麼？
如果你有房貸，銀行會要求你每個月多付一筆錢，存進一個「專用帳戶」，這個帳戶叫：
Escrow Impound Account（托管扣款帳戶）
用途只有兩個：
- Property Tax（地產稅）
- Home Insurance（房屋保險）
銀行每個月從你的房貸月供收一些錢 → 存進 Impound →
等到房屋保險到期、地稅到期，銀行會替你付款。
你沒有選擇，銀行會強制要求。
📌 2. 每月 Impound 是怎麼算出來的？
公式非常簡單：
(年度房屋保險 + 年度房屋地稅) ÷ 12
例如：
- 保費 $1,800/年
- 地稅 $12,000/年
Impound = (1,800 + 12,000) ÷ 12 = 每月多付 $1,150
這就是為什麼房貸月供不是「只有房貸」而是：
PITI：Principal + Interest + Tax + Insurance
📌 3. 為什麼保費變動會讓房貸月供增加？
原因非常簡單：
你的 Impound 是基於年度保費計算的。
所以當保費增加時 → Impound 也必須增加。
例如：
你的保費從 $1,800 → $2,600
差額 = $800
銀行會：
- 重新計算 Impound
- 調高未來每月扣款
- 要求你補上之前的不足（通常叫“Escrow Shortage”）
📌 4. 說好的月供固定呢？為什麼又變高了？
很多房主以為只要是固定利率（fixed mortgage）就「月供永遠不會變」。
錯誤觀念！
只有 P&I（本金和利息）固定不變。
地稅和保險費不固定，所以 PITI 會變。
📌 5. 加州 2024～2025 的房屋保費變動會造成什麼情況？
因為 surcharge（全州附加費）開始收，加州保費大幅提高，很多房主會看到：
- 每月房貸月供突然提高
- 收到“Escrow Shortage”補款通知
- 銀行要求一次補足差額
- 或分 12 個月攤還（但月供會變更高）
這不是銀行的錯，也不是你做錯什麼。
是整個加州保費全面上漲導致的。
📌 6. 如果收到 Escrow Shortage 該怎麼辦？
你通常有三個選項：
- 一次性付清 shortage → 月供回到最低
- 分 12 個月攤還 shortage → 月供 moderately 上升
- 接受銀行的新 PITI（包含新保費） → 月供明顯上升
如果你預計換保險或預計收到 refund，一次性付清可以避免月供長期升高。
📌 7. 如何減少未來 Impound 的壓力？（三個技巧）
- 每年保費續約前提前比價（避免漲太多）
- 避免讓保險 lapse（會導致更貴）
- 地稅每年可上訴（尤其新買房的 first reassessment 過高時）
📌 結語
Impound（托管扣款）是加州買房最容易忽略的部分。
但只要理解它的計算方式，你就會知道月供上升不是銀行為難你，而是保費與地稅自然變動造成的。
本篇完成「加州房屋保險 × 初學者系列」的第四篇，也是最實務的一篇，幫你搞懂保費、地稅與房貸之間的真正關係。
此外，2024–2025 起全加州房主都會被收取 surcharge（附加費）：
👉 加州房屋保險 surcharge 是什麼？為什麼大家都要付？
🏦 What Is Escrow Impound? Why Insurance Changes Increase Your Mortgage Payment (2025 Guide)
Many California homeowners are surprised when their lender suddenly says: “Your escrow account is short, and your monthly mortgage will increase.” With recent statewide insurance hikes and new surcharge fees, more homeowners are seeing unexpected payment changes.
This guide explains in simple terms what escrow impound is and why insurance and tax changes directly increase your monthly mortgage payment.
📌 1. What Is an Escrow Impound Account?
If you have a mortgage, your lender requires you to deposit extra money each month into a separate account called:
Escrow Impound Account
This account is used only for:
- Property Taxes
- Home Insurance
The lender collects money monthly → stores it in escrow → and pays your annual tax and insurance for you.
📌 2. How Is Your Monthly Impound Calculated?
The formula is simple:
(Annual Home Insurance + Annual Property Tax) ÷ 12
This amount is added to your mortgage payment to form:
PITI = Principal + Interest + Taxes + Insurance
📌 3. Why Does Insurance Affect Your Mortgage Payment?
Your escrow is based on your annual insurance cost.
If your policy becomes more expensive → your escrow must increase.
Example:
- Old premium: $1,800
- New premium: $2,600
Difference = $800
Your lender must:
- Recalculate your escrow
- Increase your monthly payment
- Charge you an “escrow shortage” to make up the past deficit
📌 4. Why Does My Mortgage Increase If I Have a Fixed Rate?
This is a common misunderstanding.
Only Principal & Interest (P&I) are fixed.
Taxes and insurance are not fixed → so your total payment (PITI) changes.
📌 5. How Does the 2024–2025 California Insurance Hike Affect Escrow?
Because of statewide insurance surcharges, many homeowners will see:
- Higher monthly mortgage payments
- Escrow shortage notices
- Requests for additional payments
- 12-month repayment options (but higher monthly cost)
📌 6. What Can You Do If You Receive an Escrow Shortage Notice?
You typically have three options:
- Pay the shortage in full → lowest monthly payment
- Spread the shortage over 12 months → moderate increase
- Let escrow adjust automatically → highest monthly payment
📌 7. How to Prevent Future Escrow Problems?
- Shop your insurance before renewals
- Avoid coverage lapses (premiums rise sharply afterward)
- Appeal your property tax if reassessment is too high
📌 Conclusion
Escrow impound is one of the most misunderstood parts of owning a home in California.
Understanding how it works helps you stay prepared when your insurance or taxes change.
This completes the fourth chapter of the “California Home Insurance Basics Series,”
tying together the relationship between premiums, escrow, and your true monthly mortgage cost.
California also introduced a statewide home insurance surcharge starting 2024–2025:
👉 California Home Insurance Surcharge Explained