What’s the Difference Between a Consent to Let and a Buy to Let Mortgage?

Sometimes life changes mean moving home sooner than expected. For one client, a change in family circumstances, a daughter starting school, and concerns about the area (including a neighbouring property becoming a potential HMO) made moving a priority.

With a mortgage deal due to expire and a partner who is self-employed and had never owned property before, the big question was: should the current property be sold or rented out?This is where understanding the difference between consent to let and a buy to let mortgage becomes essential.

Consent to Let – Short-Term Flexibility

Consent to let is when your existing residential lender gives permission to rent out your home under your current mortgage.

• It’s usually intended as a temporary arrangement.
  
• The lender may charge a small fee or increase the interest rate slightly.
  
• Crucially, you cannot usually release equity from the property.

For clients who want to “test the waters” as landlords or only plan to let out their home for a short period, this can be the simplest option.

In this case, the client’s lender could grant consent to let, but it wouldn’t allow her to release funds to help with the onward purchase.

Buy to Let Mortgage – Long-Term and Releasing Equity

A buy to let mortgage is a product specifically designed for rental properties. It’s the right choice if you plan to let the property on a more permanent basis.

• Affordability is based mainly on the property’s rental income rather than your personal salary.
  
• Switching allows you to release equity, which can be used as a deposit on a new home.
  
• Rates and fees can differ compared with residential mortgages, and deposits are often higher.

For our client, moving to a buy to let mortgage was the correct approach for a let-to-buy strategy—keeping the current property as a rental while unlocking equity for the next purchase.With an estimated value of £320,000 and an outstanding mortgage of £170,000, a 75% buy to let loan-to-value would allow a new mortgage of £240,000. This could release around £70,000 in equity, providing a contribution toward a new home deposit.

Considering the Tax Position

Rental income is taxable, and with the client in the higher-rate tax bracket, 40% of any rental profits would be due.

One option discussed was using a limited company structure:

• Profits retained in the company could be taxed at 19% (on profits below £50,000).
  
• Mortgage interest can usually be offset against rental income in a company, unlike personal ownership.
  
• There are higher mortgage rates and additional accountancy costs to factor in.
  
• Stamp duty implications were broadly the same for this scenario, whether buying in personal name or via a company.

This choice often comes down to whether the property is viewed as a short-term step or a long-term investment asset.

Affordability and the Next Home

The decision to sell or rent out the current home directly affected the couple’s borrowing capacity.

• Keeping the current property as a rental: they would need to keep the new purchase to around £400,000 to stay within affordable monthly payments of £1,500–£1,800.
  
• Selling the current property: this would release around £130,000 in equity after costs, making a purchase of £450,000 much more affordable, with monthly payments between £1,465 and £1,588.

There was also an alternative suggestion: sell the existing property and instead purchase a smaller, dedicated buy to let investment. This would separate the “home” from the “investment” decision and potentially make better use of equity.

Final Thoughts

The key difference between considering consent to let and buy to let lies in timeframes, viability and whether a release of equity is needed –

• Consent to let – short-term permission to rent out your home, no equity release.
  
• Buy to let – long-term rental product, affordability based on rental income, equity release possible.

For anyone weighing up the options, the decision often hinges on future plans. If the property is only being let for a short while, consent to let may be enough. If it’s intended as a longer-term investment, or if you need to unlock equity to move forward with a new purchase, buy to let is usually the correct route.

Professional advice is essential to weigh up not just the mortgage options, but also the tax position, affordability, and long-term financial goals.

Your home may be repossessed if you do not keep up repayments on your mortgage.

Some forms of Buy to Let mortgages are not regulated by the Financial Conduct Authority.

There may be a fee for mortgage advice. The precise amount will depend upon your circumstances.

Symmonds de Lacey is a trading style of Easy Street Financial Services Ltd, which is authorised and regulated by the Financial Conduct Authority. Registered in England and Wales. Company number 6430453. Registered address: Basepoint, 377-399 London Road, Camberley, Surrey, GU15 3HL.

We are not tax advisers. For tax advice, please speak to your accountant or a qualified tax adviser.

Information correct at time of writing – November 2025.