Portfolio landlord mortgages

The four-property threshold

The PRA (Prudential Regulation Authority) rules introduced in 2017 define a portfolio landlord as anyone with four or more mortgaged buy-to-let properties. Below that line you are a small landlord and the case is underwritten property by property. At or above the line, the lender treats your whole book as a single underwriting exposure. Some lenders will not work with property portfolio landlords at all. Others specialise in the segment.

What lenders look at

Aggregate portfolio loan-to-value (LTV, often capped at 75% across the book), aggregate ICR (Interest Cover Ratio) on a stressed rate, the number of properties already with that lender, the geographic spread, and the property mix (single-lets, HMOs, holiday lets, multi-unit blocks). Many lenders also impose a hard cap on number of properties they will fund per borrower (often 5 to 10).

Documentation lenders want

An up-to-date portfolio schedule (each property, value, rent, lender, loan, end date), a profit-and-loss statement for the rental business, the last two SA302s if held in personal name, or two years of company accounts if held in an SPV (Special Purpose Vehicle). The schedule is the document portfolio cases live or die on. We rebuild it properly before the first application.

Worked example, four-property portfolio aggregate test

Four properties: total value £1,200,000, total mortgage debt £860,000, aggregate LTV 71.7%. Combined gross rent £5,300 a month (£63,600 a year). Mortgages are mainly interest-only at 4.5% to 5.0%. Aggregate annual interest at portfolio average rate around £42,000. ICR at 145% requires rent of at least £60,900, which is met. The fifth purchase has to clear the new aggregate test (75% LTV across all five, 145% ICR across all five). We model both the new property and the post-purchase aggregate before submitting; failing the aggregate test is the most common reason a fifth-property application stalls.

Limited company versus personal name at scale

Above 5 to 6 properties, almost every portfolio is more efficient in a limited company because of Section 24. Personal-name portfolios can keep working but tax-drag often cancels rental profit. We model the cost of incorporating an existing personal portfolio (CGT, SDLT including the 5% additional-property surcharge, lender refinance fees) against the long-term tax saving. On a four-property personal portfolio worth £1,200,000 with cumulative gains, incorporation costs typically £100,000 to £160,000 in tax and fees up front, paying back through tax savings inside 5 to 7 years for a higher-rate taxpayer.

Lender exposure caps and diversification

Most lenders cap how much they will lend to one borrower or borrower group, often at 5 to 10 properties or a total exposure of £3 million to £5 million. If 80% of your portfolio is concentrated with one lender, the next purchase has to find a new lender. We map exposure across the panel and plan diversification before the next acquisition rather than after.

Common pitfalls we see

Building a portfolio with one lender for "simplicity" then hitting their exposure cap on the fifth deal. Buying a property that fails the aggregate ICR test and only finding out at the new lender stage. Treating the fifth purchase like the fourth (very different underwriting). Not refreshing the portfolio schedule between purchases. We work the schedule end to end and plan the next two acquisitions, not just the current one.

Buy-to-let warning

Most buy-to-let mortgages, including portfolio buy-to-let, are not regulated by the Financial Conduct Authority. Consumer Duty rules and FOS access can be limited at scale. Take advice on each new acquisition rather than treating the next deal as a copy of the last.