When the payment is smaller than the interest, the balance grows

What follows is an argument about growing loan balances, and about where the received version of it stops being true.

The condition in one sentence

A balance falls only when the payment exceeds the interest and charges applied in the same period. Where the payment is smaller, the unpaid portion of the interest is added to the balance and then attracts interest itself.

This is sometimes described as negative amortisation, and it is arithmetic rather than a penalty or a trick. It can occur on any agreement where the required or actual payment is not linked to the interest being charged. The borrower is paying every month, in good faith, and the debt is nonetheless increasing.

Where it commonly happens

Revolving credit with very low minimum payments can approach this condition, particularly where the rate is high and fees are being added. Overdrafts used continuously can exhibit it, because charges are applied to a balance that is never brought back to zero. Some deferred or interest-rolled agreements are structured this way deliberately, with the balance designed to grow until a later event.

It also appears where an arrangement to pay a reduced amount has been agreed but interest has not been frozen. That last case is the most damaging, because the borrower believes a solution is in place while the position deteriorates.

How to spot it on a statement

Compare the closing balance across three consecutive statements while noting the payments made in between. If payments were made and the balance is level or higher, interest and charges are exceeding what is being paid. The statement usually shows interest and fees as separate lines, which makes the comparison straightforward once you look for it.

For most households, many statements in regulated markets also include a projection of how long repayment will take at the current payment. A projection running to decades, or a statement that repayment will never occur, is the same information stated plainly.

Why it persists unnoticed

A payment leaving the account each month creates a strong impression of progress that the balance does not support. Statements are often reviewed for the payment amount rather than for the trend in the balance.

On the balance sheet, where the balance moves slowly, several years can pass before the pattern becomes obvious. Charges applied for exceeding a limit or missing a payment accelerate the process precisely when attention is lowest.

The remedy begins with observation, because the arithmetic is unambiguous once the numbers are put side by side.

Breaking the condition

Any payment above the interest and charges reduces the balance, so the threshold to reverse the trend is knowable and specific. Calculating that threshold from a recent statement gives a concrete target rather than a vague intention to pay more. Where the threshold is unaffordable, the position needs restructuring rather than more effort.

On the balance sheet, lenders can sometimes freeze interest or charges in cases of hardship, which changes the threshold immediately and substantially. That option generally has to be requested, and free debt advice services request it routinely on behalf of borrowers.

This is general information, not advice about your particular position.

Getting help early

The options available narrow as balances grow, so the value of acting is highest at the point the pattern is first noticed. Free, independent debt advice exists in most countries and is not the same as commercial debt management offered for a fee.

Advisers can assess the whole position rather than one agreement, which usually reveals options an individual would not find. Nothing about seeking such help is recorded as a formal step, and it does not commit the borrower to anything. This is general information about how balances behave and not advice about your circumstances or agreements.

The takeaway

Put three statements side by side. If the balance is not falling, the payment is below the interest and the arithmetic will not fix itself.

Costs compound as reliably as returns do, and in the same direction.