Finance

Interest Roll-up

Model compounding rolled-up interest and its effect on LTV at exit.

Intermediate

Introduction

Who this is for: Borrowers on facilities where interest is retained or rolled rather than serviced.

Why it matters: Rolled-up interest compounds. On a long facility the balance can grow enough to breach the lender’s LTV covenant even if the property value holds — which triggers default without anything having gone wrong operationally.

Typical scenario: A developer on an 18-month rolled-up facility checking the balance at exit against the lender’s 70% LTV covenant.

Common mistakes:
  • Calculating rolled-up interest as simple rather than compound.
  • Not projecting the exit LTV as the balance grows.
  • Assuming an extension will be granted if the exit slips.

Inputs

Facility

£
%

months

Security

£
%

Analysis

£750,000 at 0.85% monthly, rolled for 18 months, grows to £873,429 — £123,429 of interest, of which £8,679 is compounding alone. Exit LTV is 69.9% against a 70% covenant.

This analysis provides context, not financial advice. Consult a qualified adviser before making investment decisions.

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Sensitivity Analysis

Sensitivity

Adjust the variables below to stress-test this scenario. Results update instantly.

£750,000
£0£1,500,000
0.85%
03
18
160
£1,250,000
£0£2,500,000

Export

Live Results

Balance at Exit

£873,429

Total Rolled Interest

£123,429

LTV at Exit

69.87%

Covenant Headroom

£1,571

The covenant is breached at month 18 — only 0 months beyond the planned exit. Any delay is dangerous.
Exit LTV is within 5 points of the covenant. Very little room for a valuation shortfall.
If Simple Interest£864,750
Cost of Compounding£8,679
Months to Covenant Breach18.21x