Cost of living: how to rebalance your budget when prices go up

Measure the rise before responding to it

A headline inflation figure tells you what happened to an average basket, and nobody buys the average basket. Your groceries, your energy tariff, your rent and your commute each moved by a different amount, and some did not move at all. So the first step is your own data: compare each category's total over the last three periods with the same three periods a year earlier, and write down the change per category as a number.

This usually produces a short list of categories that carry almost all of the increase — commonly groceries, energy, rent or mortgage repayments, insurance and fuel — and a long list that barely changed. Rebalancing only the short list is more effective and far less demoralising than trimming everything by a few percent.

Re-set the essentials to the real figure

For the categories that rose and cannot be avoided, raise the limit to the new figure. This feels like giving in and is the opposite: a grocery limit left at last year's number is breached every period, stops carrying information, and teaches you to ignore the budget. A limit set at what groceries now actually cost is one you can hit, and hitting it is what keeps the rest of the budget credible.

Do the same for any fixed cost that has been repriced — a rent increase, a higher mortgage repayment after a rate change, an insurance renewal. These are not decisions to make each period; they are new totals to write down once, so the variable budget can be built from what genuinely remains.

Reallocate in order of flexibility, not virtue

With the essentials re-set, the increase has to come from somewhere, and the order matters. Start with categories that are pure timing — savings contributions you can pause and restart, an accelerated debt repayment you can drop back to the minimum for a period, an annual purchase you can defer. These absorb a rise without changing daily life, and they are reversible.

Next come categories where the same outcome is available cheaper — the same groceries from a different store or own-label range, the same insurance cover from another provider at renewal, the same phone plan on a lower tier, an energy tariff switched where your market allows it. Switching costs an hour and no lifestyle change.

Only then look at discretionary spending — eating out, subscriptions, entertainment — and even there, the aim is to choose what to keep rather than to strip it out. A budget with nothing enjoyable in it is a budget that gets abandoned, and abandoning it costs more than the dinner did.

One-off or new normal? A three-period rule

Not every rise is permanent, and re-setting a limit for a spike that reverses is as misleading as ignoring a rise that does not. A simple test: a change that has appeared in three consecutive periods is a new normal and the limit should move; a change seen once or twice is a one-off until proven otherwise, and should be covered from a buffer rather than baked into the budget.

Fuel and energy are the categories most likely to spike and fall back. Rent, insurance premiums and repriced loans almost never fall back on their own, so those can be treated as permanent from the first period.

Watch also for the quieter version of a price rise — the pack that shrank while the price held. Your transactions will show the same grocery spend buying less, which appears as more frequent shops rather than larger ones. Frequency rising while the amount per shop holds is the signature.

Rebalancing on a schedule, not in a panic

Once the limits are re-set, put a date in the calendar to repeat the comparison — quarterly is enough in most years, monthly when prices are moving fast. Rebalancing on a schedule means the changes are small each time; rebalancing only when the account runs dry means they are large and arrive at the worst moment.

In Fin, each category shows its limit against what has actually been spent as transactions land, so the year-on-year comparison is a read of existing totals rather than a rebuild, and a limit that has been breached three periods running is visible for exactly what it is: a number that needs re-setting, not a lapse.