£15m Specialist BTL Is Back, Including Foreign Nationals, Large HMOs, MUBs and Top-Slicing

Octane's return to specialist buy-to-let is more commercially useful than another small rate adjustment. The lender is explicitly targeting cases where the borrower, property or affordability calculation needs a closer look.

According to the lender and reporting by Bridging & Commercial and Mortgage Solutions, residential portfolio facilities can reach £15 million. Multi-unit block loans can reach £10 million and HMO loans £3 million. Octane says there is no fixed maximum number of HMO bedrooms or MUB units, although every proposal remains subject to lending criteria.

The range also includes an option to defer 1% per annum of interest and a top-slicing approach that can use eligible income to supplement rent within the interest-coverage assessment. Those features can be especially relevant to HNW landlords and international investors buying lower-yielding assets in London and the South East.

The real change is what the lender is willing to underwrite

A standard BTL proposition can fail a case for reasons that have little to do with the landlord's underlying wealth or experience. The applicant may live overseas. The property may contain too many units. The building may be partly commercial. The rent may not meet the required interest-coverage ratio at the lender's stressed rate. Or the landlord's aggregate borrowing may exceed a bank's portfolio appetite.

Consider a foreign national acquiring an £8 million residential portfolio. The investor may have substantial liquid assets and strong external income, but several properties produce relatively low rental yields. A conventional rent-only calculation could constrain the loan before the lender properly considers the client's wider position.

Likewise, an experienced operator financing a 20-unit block or a large HMO may satisfy the economics of the project but fall outside a lender's maximum unit or bedroom count. In those situations, the decisive issue is criteria—not whether another lender is five or ten basis points cheaper.

Top-slicing can help—but it is not a way around affordability

Top-slicing allows a lender to consider eligible income outside the rent from the security property when assessing whether the interest payments are sustainable. Under Octane's published approach, rent from the security property must cover at least 90% of interest at the pay rate, with the remaining cover potentially supported by qualifying UK income.

That distinction matters. It does not mean any global income can automatically be inserted into the calculation, and it does not remove the need for evidence or lender assessment. The source, currency, stability, taxation and availability of income can all affect how it is treated. Foreign-national applicants also remain subject to permitted jurisdictions and the lender's wider requirements.

Where it works, top-slicing may help a landlord whose personal finances are strong but whose target property has a lower yield. This can be relevant for prime London or South East assets, where the rental return as a percentage of capital value can be lower even though the property and borrower are attractive.

The correct comparison should therefore establish:

• the rent available from the proposed security;
• the lender's ICR calculation and pay rate;
• which additional income sources are eligible;
• the evidence required for that income;
• the applicant's personal commitments and tax position; and
• whether the structure remains sustainable if rent, rates or income change.

Interest deferral changes cash flow, not the ultimate liability

The option to defer 1% per annum of interest can reduce the immediate pay rate. That may improve the affordability calculation and potentially allow a higher loan-to-value on a lower-yielding property.

But deferred interest is not waived interest. It remains payable. Published information indicates that the deferred amount is added to the outstanding balance and can be paid or capitalised later under the lender's terms. A borrower should understand the balance at each stage, when the deferred amount becomes payable, whether it later attracts interest and how it affects the refinance or sale exit.

This is particularly important because the maximum 80% is a gross LTV including fees and deferred interest. Gross leverage is not the same as the net cash available to complete an acquisition or release capital. A borrower comparing facilities should model the actual cash received, ongoing payments, accumulated balance and repayment amount.

Large HMOs and MUBs need property underwriting as well as borrower underwriting

No fixed maximum room or unit count removes one obvious barrier, but it does not make every large asset acceptable. The lender will still need to understand planning and lawful use, licensing, fire and safety compliance, tenancy profile, valuation methodology, local demand, management capability and saleability.

A 12-bedroom HMO is not simply a larger version of a four-bedroom rental house. Income may be stronger, but operating costs, regulatory exposure and management intensity can also be greater. The valuation may depend on whether the property is assessed on a vacant-possession, bricks-and-mortar or investment basis, subject to the valuer and lender's instructions.

A multi-unit block raises additional questions. Are all units contained within one freehold title? Can individual units be sold? Are leases already granted? Is the block fully occupied? Does the borrower plan to retain it as one investment or create separate titles later? Those factors can influence security, valuation, leverage and exit flexibility.

The new range therefore widens the conversation; it does not replace proper due diligence.

Foreign-national eligibility is only the starting point

For an international investor, the statement that foreign nationals are accepted is useful—but incomplete. The finance assessment may also involve residence, nationality, permitted jurisdiction, UK credit footprint, ownership vehicle, banking arrangements, source of wealth and funds, existing UK assets and the income being used for top-slicing.

An overseas borrower acquiring several UK properties at once may need to compare a single portfolio facility against separate loans on individual units. A portfolio structure can simplify administration and support scale, while separate charges may preserve the ability to sell or refinance individual properties more easily. Neither route is automatically superior.

The borrower's lawyers and tax advisers should approve the ownership structure. Willow's role is to establish how that agreed structure affects lender appetite, security, loan size, cost and future flexibility.

Semi-commercial and refurbishment cases add another layer

Octane's published criteria include semi-commercial assets where the commercial element represents up to 50% of value. The range also permits self-funded light refurbishment costing up to 10% of the property's market value and offers up to six months' interest retention for qualifying untenanted properties.

Those features may help where an investor is buying an asset that needs modest works before letting. However, the scale and nature of the works must fit the lender's definition of light refurbishment. Structural change, planning dependency or a substantial development programme may require bridging or refurbishment finance instead.

For mixed-use property, the commercial tenant, lease, vacancy risk and proportion of residential and commercial value can materially affect terms. The correct category of finance should follow the asset and business plan rather than the label used in the sales particulars.

Which historic cases should be rechecked?

The relaunch creates an immediate database and pipeline opportunity. Cases that were declined or constrained because of foreign-national status, ICR, HMO size, MUB unit count, semi-commercial use or aggregate portfolio exposure deserve a fresh review.

A useful Specialist Portfolio Recheck should capture the borrower and ownership structure, residence and nationality, full portfolio schedule, proposed security, current and market rent, external UK income, existing debt, required leverage, works, exit and future acquisition plans.

The purpose is not to resubmit every case to Octane. It is to identify which cases now have a wider lender universe and benchmark the relaunched proposition against specialist banks, other BTL lenders and private-bank or commercial structures where appropriate.

How Willow Private Finance can help

Willow works with foreign nationals, portfolio landlords and investors financing specialist UK property. We can assess the borrower, complete portfolio, property type, rental profile and wider income before comparing the relevant lenders.

For a large case, that comparison should go beyond the initial rate. It should examine net proceeds, gross and net LTV, ICR, top-slicing, interest deferral, fees, security structure, property release terms, future acquisitions and the intended exit.

Explore Willow's buy-to-let mortgage services, or ask us to recheck a case that previously fell outside mainstream criteria.