Could a 100% mortgage help your child buy a home without a deposit?

Could a 100% mortgage help your child buy a home without a deposit?

For many first-time buyers, the biggest barrier to getting on the property ladder isn’t the mortgage payment—it’s the deposit. If your child (or grandchild) is renting and finding it difficult to save, a 100% mortgage (often described as a no-deposit mortgage) may be worth understanding.

A 100% mortgage is designed to let an eligible borrower buy with no deposit contribution from their own funds—so the loan is typically set at 100% of the purchase price. While this can reduce the upfront hurdle, it doesn’t remove the need to plan carefully for affordability, ongoing costs, and future options.

How a 100% mortgage typically works

A 100% mortgage is still a standard repayment mortgage in structure: the borrower repays the loan over time, usually with a fixed interest period at the start.

Some products may include features that can affect the interest rate during the fixed period (for example, where the rate changes as the loan-to-value (LTV) improves). The exact approach depends on the specific product terms.

Other features that may matter to first-time buyers include:

• Fixed-rate periods (for budgeting and payment stability)
• Overpayment options (to reduce the balance faster if circumstances allow)
• Early repayment terms (including whether any early repayment charges apply)

Even where a mortgage is described as “no deposit”, the lender will still assess the borrower’s ability to afford the monthly payments and manage the overall risk.

Who 100% mortgages are usually designed for

100% mortgages are typically aimed at borrowers who:

• Are first-time buyers (or otherwise meet the product’s specific “first purchase” definition)
• Have a stable income that supports the mortgage payments
• Can pass a credit assessment and affordability checks
• Are buying a property that fits the product’s property type and value parameters

Many products also have product-specific rules such as:

• Age limits (often based on age at the end of the mortgage term)
• Minimum household income
• Property type restrictions (for example, some products may exclude flats or new builds)
• Purchase price thresholds

Because these rules vary by lender and product, it’s important to check the exact criteria for any 100% mortgage being considered.

What costs still need to be budgeted for

A no-deposit mortgage can help with the deposit requirement, but it does not remove other buying costs. For a realistic plan, it’s useful to separate “deposit” from “total cash needed at purchase”. Common items include:

• Stamp Duty Land Tax (SDLT) (where applicable)
• Solicitor and conveyancing fees
• Mortgage valuation and survey costs
• Moving and set-up costs

If your child is relying on a 100% mortgage, these additional costs can be the difference between a smooth purchase and a stressful scramble for funds.

The key risks to understand before going 100%

A 100% mortgage can be attractive, but it comes with trade-offs. The main consideration is that borrowing 100% of the property value can increase exposure if house prices fall.

1) Negative equity risk

With a higher LTV from the start, there is a greater chance of being in negative equity if the market declines. Negative equity can make it harder to:

• Move to a new property
• Remortgage on different terms
• Release equity in the future

2) Affordability pressure

Even if the deposit hurdle is removed, the mortgage payment still needs to be affordable. Lenders assess affordability using income, existing commitments, and financial resilience.

3) Future flexibility

If circumstances change—such as job loss, illness, or a need to relocate—having less equity can reduce options. Planning for contingencies (such as savings for emergencies) can be particularly important.

If you’re a parent or grandparent: how you can support

If you’re helping your child, it can be useful to think about support in two different ways:

• Supporting the purchase process (for example, helping them understand the paperwork, budgeting, and timelines)
• Supporting the overall financial picture (such as ensuring they have funds for the non-deposit costs)

A 100% mortgage may reduce the need for a deposit, but it doesn’t automatically solve every cash-flow challenge. Being clear about the total costs and ongoing commitments can help your child make a more confident decision.

What to check when considering a 100% mortgage

Before exploring any no-deposit option, it’s sensible to review:

• The exact eligibility criteria (income, age, property type, purchase price)
• The repayment structure (fixed term length and how the rate behaves)
• Overpayment and early repayment terms
• Total upfront costs beyond the deposit
• Affordability assumptions and whether the payments remain manageable under realistic scenarios
• Potential future constraints if they need to move or remortgage

Is a 100% mortgage right for everyone?

Not necessarily. A 100% mortgage can suit some first-time buyers—particularly where saving a deposit has been the main obstacle and where affordability is clearly sustainable.

However, because it increases exposure to market movements and reduces equity from day one, it’s best approached with a clear understanding of the risks and the full cost of buying.

If your child is considering this route, focusing on affordability, total purchase costs, and long-term flexibility can help determine whether a no-deposit mortgage is a sensible fit for their circumstances.

This guide is educational and does not replace regulated advice. Mortgage suitability depends on individual circumstances and the specific product terms.