Checking This Year's Bills Against Last Year's

Put this year's bill beside the same period last year and separate the difference into three causes: the price changed, your usage changed, or something is wrong. Price rises are market facts to plan around. Usage rises are household information. Errors and unexplained jumps are worth a phone call. Most households never separate the three, so every increase feels like fate. The comparison takes an hour a year for your main bills and belongs on the annual money calendar in the month before your biggest contract renews.

Compare like with like: same season, same household where possible, and usage units first, money second. The money figure mixes price and usage together. The units tell you which one actually moved.

For each main bill, energy, water, phone and broadband, insurance, gather this year's figure and last year's for the same period. Write the unit usage for both, the unit price for both, and the total. Then ask in order: did the price per unit change, and by roughly how much? Did usage change, and can the household explain it, a colder winter, a new appliance, a person more at home? Anything left over after those two answers is your query list, and it is usually short.

Keep the workings on one sheet per year, filed with the bill, because next year's comparison needs this year's as its base. Three years of sheets become a household price history no provider can argue with, and the file takes less space than a single paper bill. The record-keeping guide, record-keeping for household money, shows where this sheet lives.

A usage rise with a known cause is not a problem to fix, it is a fact to budget: the baby, the home-working year, the teenager's legendary showers. A usage rise without a cause is the comparison's most valuable catch, because it often points at something physical: a running leak, a failing appliance heating water all night, a heater left on a timer nobody remembers setting. The Department of Energy and WaterSense guidance listed below helps households read energy and water use appliance by appliance when a number needs explaining.

Hypothetical: a household's water usage is up by a fifth year on year, price flat, household unchanged. The comparison cannot say why, but it turns a vaguely high bill into a specific hunt that finds a toilet cistern running silently, day and night, for months. Without the side-by-side figures, that bill would simply have been paid, at the new level, as the new normal.

A pure price rise invites a different response: comparison and switching, done calmly in the renewal month rather than angrily on the bill's arrival. Gather the market alternatives for the same usage, compare total annual cost at your usage rather than headline rates, and count switching costs and exit fees honestly. Sometimes the current deal, risen, is still competitive, and the comparison's gift is peace of mind rather than a move. Either outcome beats not knowing.

Watch the quiet price changes hardest: introductory rates expiring, discounts falling off, tariffs renamed so last year's figure has no obvious twin. Providers count on annual amnesia. A one-page sheet per year is the household's memory, written down, and it converts each renewal from a first encounter into a negotiation with evidence.

Estimated bills deserve a special mark on the sheet. An estimate compared against an estimate proves nothing, and a long run of estimates often ends in one corrective bill that looks like a catastrophe. Where you can, supply real readings before the comparison month, so the year-on-year figures are both honest. If a bill is plainly wrong, meter misread, wrong tariff applied, a closed account still billing, contact the provider with the two bills in hand. Documented comparisons get resolved. Feelings about bills get apologies.

Set a threshold for effort: query any unexplained difference big enough to matter to your household, and let small mysteries go after one check. The comparison is an annual hour, not a licence to litigate every line. Its job is catching the significant and the repeating, and a difference that repeats is significant by definition, whatever its size.

That is the entire discipline: this year, last year, price separated from usage, surprises investigated once. It is unglamorous bookkeeping, and it is one of the highest-value hours in this whole cluster, because it audits reality rather than intentions.

Start with whichever bill annoys you most. Annoyance is good data about where the unexplained money sits, and one completed comparison will teach you the method faster than any description of it, this one included.