When money feels tight, a lower monthly payment can sound like exactly what you need.

And sometimes it genuinely can help.

But there’s a catch people often miss:

lower each month does not always mean cheaper overall.

In fact, spreading debt over a much longer mortgage term can leave you paying thousands more.

Let’s put some numbers on it.

A Peterborough example

Imagine a homeowner with:

• a £180,000 mortgage 
• £20,000 of unsecured debt
• around 20 years left on the mortgage.
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Let’s say the mortgage rate is 5.5% and the unsecured debt is costing around 18%.

On those numbers, the combined monthly payments come to roughly £1,826.

Now imagine rolling the whole £200,000 into a new 25-year mortgage at 5.5%.

The monthly payment drops to about:

£1,228

That’s around:

£598 less every month

Which sounds brilliant.

But now look at the total.

The sting is in the long term

Under the original setup, the scheduled repayments come to roughly:

£325,367

Under the new 25-year mortgage, the scheduled repayments rise to around:

£368,452

Add an illustrative £2,000 in fees and you're at roughly:

£370,452

That’s about:

£45,000 more overall

So yes, the monthly payment is lower.

But the debt hangs around for much longer.

And that extra time costs money.

Why does this happen?

Simple.

You are taking debt that might have been cleared in four years and stretching it across 25.

Even with a lower interest rate, you’re paying interest for much longer.

That’s why the monthly payment drops.

It’s not magic.It’s time.

There’s another big difference too

Credit cards and personal loans are normally unsecured.

A mortgage is secured on your home.

So if you roll unsecured debt into the mortgage, you may be turning debt that was not secured against your house into debt that is.

That changes the risk.

If you cannot keep up the mortgage payments, your home can ultimately be at risk.

That doesn’t mean consolidation is always wrong.

It does mean the decision deserves more than:

“Can I get the payment down?”

Ask these questions instead

Before agreeing to anything, ask:

What will I repay in total?

How many extra years will I be paying?

What fees are being added?

Are there early repayment charges?

Which debts will now be secured against my home?

What happens if rates rise?

What other options have I looked at?

Those questions tell you far more than the monthly payment on its own.

The bit people forget

A lower payment can be genuinely important if your household budget is under pressure.

Freeing up £500 or £600 a month could make a huge difference.

But that relief comes at a price if the debt lasts another decade or more.

And if you are already struggling with mortgage payments, adding more debt to the mortgage can increase the amount secured against your home.

That needs careful thought.

MoneyHelper recommends looking at the total amount payable, fees, APRC and the risks of secured borrowing not just the monthly figure.

The FCA has also warned about the cost of stretching repayment terms and turning unsecured debt into secured debt.

So is consolidation a bad idea?

Not automatically.

For some people, it may be the right move.

But it needs to be judged on the whole deal, not the bit that looks nicest on the first page.

The monthly figure is only one number.

Sometimes the number that really matters is:

how much will this cost me by the time it is finally paid off?