Mortgage Toolkit · v3

Your mortgage.
The full picture.

Four strategies. One question: which route gets your money working hardest — on the debt, in savings, or compounding in the market?

A Baseline
B Overpay Monthly
C Build & Clear
D Build & Hold
◆ YOUR MORTGAGE ◆

01 — Mortgage Details

Your mortgage — what you owe and what it costs
£
%
yrs
Your Monthly Payment
Calculated from your inputs £ —
My payment differs from this →
◆ EXTRA PAYMENTS ◆

02 — Overpayments

What you can put in extra — used differently in each strategy
£
£
Enter your balance above to see your overpayment cap
⚠ Lender cap likely exceeded. Most lenders limit overpayments to 10% of the outstanding balance per year before early repayment charges apply. . Check your mortgage terms before proceeding.
◆ THE LONG GAME ◆

03 — Investment Return & Time Horizon

Where the money goes — investment return rate and your horizon
%
yrs
£
Investment return applies to all investments throughout — existing pot, one-off, and monthly overpayment. 7% is the long-term FTSE global index reference, not a prediction.

Strategy C: ISA holds your existing pot + one-off from day one. Monthly overpayment is added each month. Mortgage pays standard. When the ISA total reaches the remaining mortgage balance — the ISA is liquidated, debt cleared, pot resets. The chart shows the dip at that moment and the rebuild after.

Strategy D: same ISA approach, same monthly contributions — but the mortgage runs its full term. No liquidation. The freed payment joins the pot at term end.
◆ YOUR RESULTS ◆

Key Numbers

Largest Long Game Pot
—
B — Interest Saved vs A
—
Mortgage-Free
—
Long Game Pot
—

Strategy Comparison

Wealth Position Over Time
Liquid investment pot across all four strategies. C and D start identically and track together — until C's ISA reaches the mortgage balance and is liquidated (visible dip). C then rebuilds with the freed mortgage payment. D compounds without interruption to full term.
◆ The Wealth Engine
—
—

Year-by-Year Breakdown

Year-by-Year Breakdown

A & B show mortgage balance remaining before payoff — B's should be lower each year due to overpayments. After payoff both switch to investment pot. C & D show ISA value throughout (italic = pre-crossover / pre-term).

For financial education purposes only — not financial advice. All figures are illustrative, based on inputs provided, and assume fixed rates throughout. Actual mortgage overpayment limits (typically 10% per year) and early repayment charges vary by lender — always check your mortgage terms. Savings and investment returns are not guaranteed and will vary. The 7% investment return is a long-term reference figure, not a prediction. Past performance is not a guide to future returns. Speak to a qualified financial adviser before making significant decisions. f.it finance — Module 5.