Building Society Buy-to-Let Mortgage Guide UK

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UK Landlord Mortgage Guide • September 2026

Building Society Buy-to-Let Mortgage Guide UK

A building society buy-to-let mortgage is designed for a property you intend to rent to tenants rather than occupy as your own home. The lender normally looks closely at expected rent, loan-to-value, property type and your landlord profile instead of assessing the application in exactly the same way as a standard residential mortgage.

Building societies can be particularly useful for first-time landlords, smaller portfolios and cases where a more specialist approach is needed. But there is no single “best building society” for buy-to-let: maximum LTV, rental-cover calculations, portfolio limits, property criteria, personal-income requirements and limited-company rules differ materially between lenders.

Compare Building Society Routes Check Rental Cover See Application Steps
Investment and mortgage warning: rental income is not guaranteed. Your rental property could be repossessed or a receiver of rent appointed if you do not keep up mortgage repayments. Most business buy-to-let mortgages are not regulated by the Financial Conduct Authority in the same way as residential mortgages.

Meaningful editorial review: 27 September 2026. Buy-to-let rates, stress rates, rental-cover calculations, landlord law and tax treatment can change. Check the lender, HMRC and the relevant national housing authority before acting.

Building Society Buy-to-Let Mortgages: Quick Answers

Typical deposit Around 25% is common, meaning 75% LTV. Some societies offer selected products at higher or lower LTVs.
Main affordability test Expected rental income normally needs to cover the stressed mortgage interest by the lender’s required Interest Coverage Ratio.
Common repayment method Many buy-to-let mortgages are interest-only, although repayment and part-and-part options exist with selected societies.
First-time landlords Some societies accept them; others require applicants to own or occupy another residential property.
Portfolio landlords Four or more mortgaged buy-to-let properties commonly triggers additional portfolio underwriting.
Limited companies Standard personal BTL ranges do not always accept companies. Specialist or broker-only products are often used.
Most BTL mortgages Commercial buy-to-let lending is generally outside ordinary FCA mortgage regulation, although consumer buy-to-let has a separate framework.
Landlord law England, Wales, Scotland and Northern Ireland have different tenancy, registration and property-management rules.
Fast answer: start with the property’s realistic monthly rent and your available deposit. If the rent does not pass the lender’s stress and rental-cover calculation, a larger deposit may be needed even if your personal salary is high.

What Is a Buy-to-Let Mortgage?

Buy-to-let finance is for a property being acquired or held mainly as a rental investment. Unlike a normal residential mortgage, the amount you can borrow is often strongly linked to the rent a suitably qualified valuer believes the property can achieve.

Lenders still examine your credit record, age, experience, property type and sometimes personal income. But a landlord cannot usually compensate for weak rental coverage simply by saying the property might rise in value later.

Residential mortgage

  • Designed mainly for your own home.
  • Affordability is centred on household income and expenditure.
  • Usually regulated as a residential mortgage.
  • Letting the whole property normally requires lender permission.

Buy-to-let mortgage

  • Designed for a property rented to tenants.
  • Rental income and ICR are central to affordability.
  • Most commercial BTL lending is not ordinary FCA-regulated mortgage business.
  • Interest-only borrowing is common.

MoneyHelper Buy-to-Let Mortgages Explained

After opening this link:

  1. Read the section explaining how buy-to-let differs from a residential mortgage.
  2. Check the rental-cover explanation.
  3. Review the interest-only section before comparing monthly payments.
  4. Read the guidance for accidental landlords if you already own the property.
  5. Do not assume every BTL mortgage has the same regulation or consumer protection.

Building Society Buy-to-Let Routes Worth Comparing

The examples below show how different building societies approach landlord lending. They are not rankings or personal recommendations. Criteria and mortgage products can be changed or withdrawn.

Society
Current approach
Useful distinction
Skipton
Standard buy-to-let lending with interest-only, repayment and part-and-part options.
Current published criteria include at least a 25% deposit, rental cover of 125% under its stated example and minimum personal income of £20,000.
Leeds
Standard BTL, HMO and holiday-let routes, with additional specialist lending.
Limited-company and portfolio-landlord applications are broker-only. Leeds states that a 25% deposit is commonly required.
Principality
BTL lending in England and Wales, including eligible first-time landlords.
Current maximum is 75% LTV; applicants should be 21 or over and collectively own no more than three mortgaged BTL properties under the published criteria.
Coventry
Products for new and existing landlords, including portfolio criteria.
Limited-company landlord products sit outside Coventry’s standard BTL range and are available through its specialist Godiva Mortgages route via brokers.
Tipton
Specialist BTL range with fixed and discount options.
Its current product finder includes selected BTL products reaching 80% LTV, subject to individual product criteria.
Why criteria matter more than a headline rate: a 5% rate from a lender that requires 25% deposit is irrelevant if you only have 20%. Likewise, a lower rate can be more expensive after a large product fee or if the property’s expected rent fails the lender’s stress test.

Official Skipton Skipton Buy-to-Let Mortgages

After opening this link:

  1. Check the minimum deposit currently required.
  2. Read the rental-cover requirement.
  3. Check the minimum personal-income rule.
  4. Choose between interest-only, repayment or any eligible part-and-part option.
  5. Use Skipton’s current product finder rather than relying on an old quoted rate.

Official Leeds Leeds Building Society Buy-to-Let

After opening this link:

  1. Choose standard BTL, HMO, holiday let, portfolio or limited-company lending.
  2. Check whether your route can be handled directly or must go through a broker.
  3. Review the required deposit and property criteria.
  4. Use the rental-affordability tool if appropriate.
  5. Open the current product page and check its rate, fee, LTV and Early Repayment Charge.

How Much Deposit Do You Need for a Buy-to-Let Mortgage?

A 25% deposit is a common starting point for mainstream buy-to-let lending. That means borrowing 75% of the property value. Some lenders permit higher LTVs, while lower-LTV products can have different pricing or rental-cover outcomes.

Property price
25% deposit
75% mortgage
£150,000
£37,500
£112,500
£200,000
£50,000
£150,000
£250,000
£62,500
£187,500
£300,000
£75,000
£225,000
Deposit is not the full cash requirement. A landlord may also need money for additional-property tax, conveyancing, valuation or survey, mortgage fees, licensing, safety work, insurance, initial repairs and a reserve for empty periods.

Interest Coverage Ratio: The Buy-to-Let Test That Often Decides the Loan

The PRA expects lenders within its scope to assess whether expected rent can support mortgage interest through an Interest Coverage Ratio, or use an appropriate income-affordability assessment where personal income is being relied on.

In simple terms, the lender applies a stressed interest rate and then requires the rent to exceed that stressed mortgage interest by a set percentage. The exact ICR can differ by lender, product, taxpayer status and applicant type.

125% A common lower-end rental-cover percentage in parts of the BTL market.
145% Also commonly encountered, particularly where a lender uses a more cautious tax or affordability assumption.
Stress rate The lender may test the mortgage at a rate above the actual initial mortgage rate.
Rent evidence The expected market rent normally needs independent valuation or other acceptable evidence.
Illustrative calculation only: if stressed mortgage interest were £900 a month and the lender required 145% coverage, the rent would need to be about £1,305 a month. A different lender may use another stress rate or ICR.

Official Bank of England / PRA Buy-to-Let Underwriting Standards

After opening this link:

  1. Open the current supervisory statement rather than an old summary.
  2. Find the affordability-testing section.
  3. Read the definition of Interest Coverage Ratio.
  4. Note that expected rental income should be appropriately verified.
  5. Remember that individual lenders can apply criteria stricter than the regulatory minimum expectations.
2027 regulatory update: the PRA published an updated version of its BTL underwriting supervisory statement in January 2026 that becomes effective from 1 January 2027. Applications made later should be checked against the rules and lender criteria then in force.

Interest-Only vs Repayment Buy-to-Let

Many landlords use interest-only borrowing because the monthly mortgage payment is lower than an equivalent capital-and-interest mortgage. The trade-off is important: the mortgage balance normally remains outstanding and must be repaid at the end.

Interest-only BTL

  • Monthly payment generally covers interest only.
  • Can improve monthly cash flow.
  • The original capital usually remains due at the end.
  • You need an acceptable repayment strategy.
  • Selling the property may be part of that strategy where the lender accepts it.

Repayment BTL

  • Each scheduled payment includes interest and capital.
  • Monthly cost is usually higher.
  • The loan reduces over the mortgage term if payments are maintained.
  • Can build equity without relying only on house-price growth.
  • Rental cover still needs to meet lender requirements.
Do not call an interest-only monthly payment “the cost of owning the property”. You still need to allow for maintenance, insurance, empty periods, agent fees, tax, compliance work and repayment of the mortgage capital.

First-Time Landlord, Portfolio Landlord, HMO or Accidental Landlord?

First-time landlord Some building societies accept applicants with no previous landlord experience. Others impose extra income or home-ownership criteria.
Portfolio landlord Four or more mortgaged rental properties commonly triggers portfolio underwriting, including review of the wider portfolio.
HMO landlord Houses in Multiple Occupation can require specialist finance and may need local-authority licensing depending on the property and location.
Holiday let Holiday-let lending is usually treated differently from a standard tenancy-based BTL mortgage and has separate income and property criteria.
Accidental landlord You may have inherited a property or moved out of your former home. Consumer buy-to-let rules can become relevant depending on circumstances.
Let-to-buy You retain and rent your current home while buying another property to live in. Both mortgages and the onward purchase need to work together.
Do not simply start renting out a mortgaged home. If you currently have a residential mortgage, contact the lender before letting the property. Depending on the circumstances, it may grant consent to let or require a move to suitable buy-to-let finance.

Personal Name or Limited Company Buy-to-Let?

Limited-company BTL has become a significant part of the landlord market, but setting up a company is not automatically a tax-saving shortcut. Mortgage pricing, product fees, accounting costs, extraction of profits, capital gains and future plans all matter.

Buying personally

  • Wider choice among some mainstream building-society BTL ranges.
  • Rental profit is generally taxed as personal property income.
  • Individual residential landlord finance-cost restrictions can apply.
  • Tax depends on your wider personal circumstances.

Buying through a company

  • Requires a lender that accepts the company structure.
  • Can involve broker-only specialist products.
  • Company tax and mortgage-interest treatment differs from an individual landlord.
  • Taking money out of the company can create additional tax consequences.
Do not transfer an existing personally owned rental property into a company solely because you have seen a tax comparison online. A transfer can create tax, legal, refinancing and transaction costs. Take qualified tax and legal advice based on your own portfolio.

Official HMRC Residential Landlord Finance Cost Tax Rules

After opening this link:

  1. Check that the example matches an individual residential landlord rather than assuming company treatment is identical.
  2. Review how the basic-rate tax reduction is calculated.
  3. Consider your other taxable income as well as rental income.
  4. Use a qualified tax adviser where company ownership, partnerships or multiple properties make the position more complex.

Buy-to-Let Tax and Purchase Costs

Landlord tax is one of the areas where a mortgage that “works” on a lender calculator can still produce a poor investment result. Purchase tax, rental-income tax and eventual disposal tax need to be considered separately.

England and Northern Ireland: Additional-Property SDLT

For transactions caught by the higher residential rates, the current rates introduced from 1 April 2025 start at 5% on the first £125,000, then rise through the higher bands. Different rules can apply to companies, non-UK residents, replacement of a main residence and other special cases.

5% Current higher SDLT rate on the portion up to £125,000.
7% Current higher rate on the portion from £125,001 to £250,000.
10% Current higher rate on the portion from £250,001 to £925,000.
Nation matters Scotland uses LBTT and the Additional Dwelling Supplement; Wales uses Land Transaction Tax with its own higher residential rates.
Example: HMRC’s current additional-property guidance shows £20,000 SDLT on a £300,000 additional residential property under the higher rates effective from 1 April 2025. Always recalculate for the actual completion date and ownership circumstances.

Official HMRC Higher Rates of Stamp Duty Land Tax

After opening this link:

  1. Check whether you will own more than one residential property at the end of completion day.
  2. Include qualifying property interests you hold outside the UK where the rules require it.
  3. Check joint-buyer and spouse or civil-partner rules.
  4. Apply any non-UK resident treatment if relevant.
  5. Ask your conveyancer to confirm the final return and tax before completion.

Rental Income and Finance Costs

Individuals normally calculate taxable property income after allowable expenses, but residential mortgage finance costs are subject to specific restrictions. HMRC’s current guidance explains the basic-rate tax reduction rather than treating all residential mortgage interest as an ordinary deductible expense for individuals.

Tax treatment can depend on whether the property is personally owned, jointly owned, held in partnership, held through a company or subject to other special circumstances. This guide does not replace tax advice.

Being Approved for a Mortgage Does Not Make the Property Ready to Let

A landlord has legal and safety duties separate from the mortgage. The rules are not identical across the UK, so check the nation and council area where the property is located.

Check gas-safety requirements where gas is supplied.
Meet applicable electrical-safety requirements.
Have the required Energy Performance Certificate.
Use the correct tenancy or occupation-contract documentation.
Protect qualifying tenant deposits correctly.
Check smoke and carbon-monoxide alarm requirements.
Check HMO and selective-licensing rules with the council where relevant.
Arrange appropriate buildings and landlord insurance.
Keep records of rent, repairs and expenses for tax purposes.
Check landlord registration where the nation requires it.
Area
Important system
Practical point
England
Renters’ Rights Act 2025 reforms
Major private-renting changes took effect from 1 May 2026, including assured periodic tenancies and the end of Section 21 no-fault possession.
Wales
Renting Homes framework and Rent Smart Wales
Welsh landlord registration, licensing and occupation-contract rules differ from England.
Scotland
Scottish private landlord registration
Check registration, tenancy, deposit and local licensing requirements before letting.
Northern Ireland
Landlord Registration Scheme
Private landlords generally must register before letting a new tenancy.

Official GOV.UK Landlord Responsibilities

After opening this link:

  1. Check the safety requirements that apply to your property.
  2. Follow the EPC and deposit-protection links where relevant.
  3. Check the right-to-rent requirement if the property is in England.
  4. Use the separate national guidance if your property is in Scotland, Wales or Northern Ireland.
  5. Then check your local council for licensing rules that do not appear in a national mortgage guide.

England Landlords: Renters’ Rights Act Changes From 1 May 2026

England’s private-rented-sector rules changed materially on 1 May 2026. Existing assured shorthold tenancies moved into the new assured periodic tenancy framework and new private assured tenancies are generally periodic rather than fixed ASTs.

Section 21 ended Private landlords can no longer rely on Section 21 no-fault possession for tenancies covered by the new regime.
Periodic tenancies Covered private tenancies now operate on the new periodic basis rather than the previous standard fixed-term AST model.
Rent increases Landlords need to follow the statutory rent-increase process under the new regime.
Possession grounds If possession is needed, the correct statutory ground and procedure must be used.
Pet requests The new rules include tenant rights to request permission to keep a pet, subject to the statutory framework.
Enforcement New landlord duties and restrictions carry enforcement provisions, so old tenancy templates should not simply be reused.

Official England guidance Renters’ Rights Act: Landlord Overview

After opening this link:

  1. Read the tenancy changes before issuing a new agreement.
  2. Check the current rent-increase procedure.
  3. Use the possession guidance if you need the property back.
  4. Do not rely on an old Section 21 template.
  5. Check for further commencement dates because not every provision necessarily starts at the same time.

EPC, Property Condition and Mortgage Eligibility

For domestic privately rented property in England and Wales covered by the Minimum Energy Efficiency Standard, the current baseline generally prevents letting an F- or G-rated property unless a valid exemption applies. Mortgage lenders can impose stricter property requirements of their own.

EPC E baseline Current domestic MEES guidance in England and Wales uses EPC E as the minimum level for covered privately rented homes unless exempt.
Green BTL products Some lenders offer separate products for properties with stronger EPC ratings such as A-C.
Condition matters A lender may refuse a property needing major work before it can safely be occupied and let.
Leasehold matters Remaining lease term, service charge, ground rent and letting restrictions can affect BTL mortgage suitability.
Flats and blocks Construction, cladding, storey height and ex-local-authority status can trigger lender-specific criteria.
HMO use A standard BTL mortgage may not permit HMO or multi-unit use. Check the intended letting arrangement before applying.

Official energy guidance Domestic Private Rented Property MEES Guidance

After opening this link:

  1. Check whether the property is legally required to have an EPC.
  2. Check the current EPC rating.
  3. If it is F or G, read the improvement and exemption rules before assuming it can be legally let.
  4. Check the lender’s separate EPC criteria.
  5. Budget for works before calculating your real investment return.

Documents to Prepare for a Buy-to-Let Mortgage

Proof of identity and address.
Deposit amount and source.
Purchase price or current valuation.
Expected monthly market rent.
Employment and personal-income details where required.
Payslips or self-employed evidence if the lender requests it.
Recent bank statements.
Details of existing residential mortgages.
Details of every existing BTL mortgage.
Portfolio schedule for portfolio-landlord applications.
Existing tenancy and rent details for a remortgage.
Company information for limited-company applications.
Portfolio applicants: be ready to provide the lender or broker with a consistent schedule showing property addresses, values, outstanding mortgages, monthly payments, rents and lender details. Underwriters may assess the wider portfolio rather than the new property in isolation.

How to Get a Building Society Buy-to-Let Mortgage

  1. Choose the landlord route. Decide whether this is standard BTL, HMO, holiday let, let-to-buy, consumer BTL, portfolio lending or a limited-company purchase.
  2. Work out available cash. Keep the deposit separate from purchase tax, fees, repairs and emergency reserves.
  3. Estimate realistic rent. Use local market evidence rather than the rent needed to make your spreadsheet work.
  4. Calculate the likely LTV. A 25% deposit means 75% LTV before fees.
  5. Check building-society criteria. Look at landlord experience, minimum income, age, property type, location and portfolio limits.
  6. Check rental-cover rules. Make sure the expected rent is likely to pass the lender’s ICR and stress-rate test.
  7. Compare mortgage products. Review rate, product fee, valuation, cashback, Early Repayment Charge and reversionary rate.
  8. Use a broker where required. Limited-company, portfolio and specialist BTL routes are often broker-only.
  9. Submit the application. Provide accurate personal, portfolio, deposit and property information.
  10. Let the lender value the property. The valuer may assess both property value and expected market rent.
  11. Complete legal work and licensing checks. Make sure the intended tenancy and property use match both lender and local-authority rules.
  12. Keep a landlord reserve after completion. Do not depend on uninterrupted rent from the first month onward.

How to Compare Two Buy-to-Let Mortgages Properly

Check
Why it matters
Question to ask
Initial rate
Changes monthly interest cost.
Is it fixed, tracker, discount or another variable rate?
Product fee
BTL fees can materially change total cost.
Is the lower rate still cheaper after the fee?
Stress test
Can change the maximum loan.
What ICR and stress rate apply to my borrower type?
ERC
Can make an early sale or refinance expensive.
How much would I pay if I sell during the deal?
LTV
Changes both pricing and required deposit.
Would a larger deposit improve the deal enough to justify tying up more cash?
Property rules
Not every lender accepts every flat, HMO, lease or construction type.
Does this lender accept the property exactly as it will be let?

Remortgaging a Buy-to-Let Property

Start reviewing the mortgage before the current deal expires. The goal is not simply to find a lower headline rate: check the outstanding balance, new valuation, resulting LTV, expected rent, Early Repayment Charge and any fee on the replacement mortgage.

Like-for-like remortgage A new lender refinances the existing balance without material additional borrowing.
Capital raising You borrow more against the property. The purpose and resulting LTV can affect lender acceptance.
Product transfer You stay with the existing lender but move to another available mortgage deal.
Portfolio refinance Changing one loan can still trigger assessment of the wider portfolio where portfolio-landlord rules apply.
PRA buy-to-let underwriting guidance contains specific treatment for certain remortgages with no additional borrowing, but the lender still applies its own current product and underwriting criteria.

Common Buy-to-Let Mortgage Mistakes

Using optimistic rent The lender’s valuer can use a lower market-rent figure than the letting agent or investor expected.
Spending every pound on the deposit A boiler failure or empty period shortly after completion can create an immediate cash-flow problem.
Ignoring tax before calculating yield Gross rent is not the same as after-tax investment return.
Using a residential mortgage secretly Letting the property without the lender’s required permission can breach the mortgage terms.
Choosing on rate alone Product fees and ERCs can be especially significant in buy-to-let lending.
Forgetting void periods Budget for periods with no rent rather than assuming twelve fully paid months every year.
Buying first, checking licensing later HMO, selective and additional licensing can materially affect the viability of a property.
Assuming company ownership is automatically cheaper Tax, mortgage pricing and extracting profits all need individual analysis.

Before Making an Offer: Landlord Numbers Checklist

Purchase price.
Cash deposit.
Expected mortgage balance.
Realistic monthly market rent.
Mortgage interest under the lender’s stress test.
Property tax on purchase.
Conveyancing and mortgage fees.
Insurance cost.
Service charge and ground rent where relevant.
Letting and management fee.
Maintenance reserve.
Void-period reserve.
Licensing and compliance cost.
Tax on rental profit.

Official Buy-to-Let and Landlord Sources

MoneyHelper Buy-to-Let Mortgage Guide PRA BTL Underwriting Standards FCA Firm and Regulation Check HMRC Additional-Property SDLT HMRC Rental Income Guidance HMRC Landlord Finance-Cost Tax Relief GOV.UK Landlord Responsibilities England Renters’ Rights Act Guidance Domestic Rental EPC / MEES Rules Northern Ireland Landlord Registration Skipton BTL Mortgages Leeds Building Society BTL Principality BTL Mortgages Coventry Landlord Mortgages Tipton BTL Mortgages

Independent Mortgage, Tax and Landlord Information Notice

Building-Society.org is an independent informational website. It is not a building society, bank, mortgage broker, financial adviser, tax adviser, letting agent, solicitor, HM Revenue & Customs, the Financial Conduct Authority or the Prudential Regulation Authority.

Buy-to-let borrowing and property investment involve financial, tax and legal risk. Mortgage eligibility depends on the borrower, property, rent, LTV, portfolio and lender. Tax treatment depends on ownership and personal circumstances.

Verify before committing: check the lender’s live mortgage product, current landlord law for the property location, local council licensing requirements and current tax rules before exchanging contracts.

Building Society Buy-to-Let Mortgage FAQs

1. Do building societies offer buy-to-let mortgages?

Yes. A number of UK building societies offer landlord mortgages, including standard buy-to-let, remortgage and selected specialist options. Some also offer HMO, holiday-let, portfolio or limited-company routes, although specialist products may be broker-only.

2. How much deposit do I need for a building society buy-to-let mortgage?

A 25% deposit is common, which corresponds to 75% LTV. Individual products can require more or less. The Tipton, for example, currently shows selected BTL products reaching 80% LTV, while Skipton’s published standard criteria state at least a 25% deposit.

3. How much rent is needed for a buy-to-let mortgage?

The exact requirement depends on the lender’s Interest Coverage Ratio and stress rate. MoneyHelper notes that lenders commonly require rental income to cover around 125% to 145% of stressed mortgage payments, but an individual building society can use different calculations.

4. Can a first-time landlord get a building society mortgage?

Yes with selected societies. Principality currently states that it accepts first-time landlords and buyers, subject to its criteria. Other lenders may require you to own or live with someone who owns a residential home, so check the individual society before applying.

5. Are buy-to-let mortgages interest-only?

Many are, but they do not have to be. Selected building societies also offer repayment or part-and-part options. With interest-only borrowing, the capital normally remains outstanding at the end of the term, so an acceptable repayment strategy is essential.

6. Are buy-to-let mortgages regulated by the FCA?

Most commercial buy-to-let mortgages are not regulated by the FCA in the same way as normal residential mortgages. Consumer buy-to-let, which can apply to some accidental-landlord situations, has a separate regulatory framework. Check the status of your own case and intermediary before proceeding.

7. Can a limited company get a building society buy-to-let mortgage?

Some building-society groups offer limited-company lending, but it is often outside the standard personal BTL range and may require a mortgage broker. Leeds, for example, states that its limited-company BTL mortgages are broker-only, while Coventry directs company landlords to specialist Godiva Mortgages products through brokers.

8. What is a portfolio landlord?

A borrower with four or more mortgaged buy-to-let properties is commonly treated as a portfolio landlord for underwriting purposes. The lender may review the performance, borrowing and rent of the wider portfolio rather than considering only the new property.

9. Do landlords pay higher Stamp Duty on a buy-to-let property?

In England and Northern Ireland, many buy-to-let purchases are subject to higher SDLT rates where the additional-property rules apply. Scotland and Wales have separate property-tax systems. Ownership structure, other properties and residence status can change the calculation.

10. Is a building society better than a bank for buy-to-let?

Not automatically. Building societies can offer useful landlord and specialist criteria, but the right lender depends on LTV, expected rent, property type, portfolio size, fees, stress testing, company structure and the mortgage products available when you apply.

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