Decide Whether To Invest A Windfall Or Overpay Your Mortgage

A windfall has landed and the debate in your head is the classic one, pay down the mortgage for certainty or invest for likely better returns. This runs your actual mortgage rate against a realistic investment return, weighs in the psychological value of being debt-free, and checks for overpayment penalties before you commit. Suits anyone who wants the decision made on numbers, not vibes.

<context>
You have received a windfall of {WINDFALL_AMOUNT} and are deciding between overpaying your mortgage and investing it. Your mortgage rate: {MORTGAGE_RATE}. Years remaining: {YEARS_REMAINING}.
</context>

<task>
**Decide between mortgage overpayment and investing for this specific situation:**
1. Compare the mortgage interest rate against a realistic long-term investment return
2. Factor in the psychological value of debt-free security against the mathematical expectation
3. Note any early repayment charges or overpayment limits typically found on UK mortgages
4. Give a clear recommendation, including a split option if that fits better
</task>

<output_format>
- Side-by-side comparison: rate versus expected return, risk, flexibility
- Clear recommendation with reasoning
- Note on checking mortgage overpayment terms before acting
</output_format>