## What changes in the model
Halal finance products can use structures such as diminishing partnership or lease-based payments. The language may differ from conventional debt, but the investor still needs to know monthly cost, fees, term, deposit, rent coverage, refinance options, and tax treatment.
The FCA's [consumer information](https://www.fca.org.uk/consumers) is a broad starting point for financial services protections. For acquisition tax in England and Northern Ireland, use the official [SDLT calculator](https://www.tax.service.gov.uk/calculate-stamp-duty-land-tax/) and get tax advice where the ownership or payment structure is unusual.
## The calculation path
Model:
- Purchase price and acquisition tax.
- Deposit and arrangement costs.
- Monthly product payment.
- Rent, voids, maintenance, insurance, and management.
- Refinance or sale assumptions.
- Cash left in and net monthly cash flow.
Do not convert the product into a standard mortgage in your spreadsheet just to make the numbers familiar. If the actual offer has a different payment profile, use that profile.
## Worked example
Suppose rent is 1,500 per month and the finance payment is 950. If operating costs and void allowance total 300, monthly cash flow before tax is 250. If a conventional template had assumed a 750 mortgage payment, the deal would be overstated by 200 per month, or 2,400 per year.
That difference can change the maximum purchase price. It can also change whether the investor has enough resilience for repairs, rent delay, or a longer refinance timeline.
## What to verify
Ask the provider and adviser how the product treats ownership share, early settlement, fees, insurance, arrears, and refinancing. Ask your accountant how the structure affects tax reporting. The goal is not to label the deal good or bad because it is halal finance. The goal is to model the real cash flows and obligations before you bid.
## What to save in the model
For this halal property finance: uk underwriting checks check, save the source links, date checked, calculator inputs, base case, downside case, professional question, and final pass or proceed decision in the deal notes. Also save who verified each assumption: broker, solicitor, council, insurer, accountant, or your own viewing notes. The article should not be the evidence itself. It is the checklist that tells you which evidence to collect, where to link it, and which calculator result changed the decision. For live deals, rerun the model whenever one assumption changes. If the answer changes, update the offer price before sharing the pack. Keep rejected assumptions visible too.