Published 14th October 2026
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A mortgage payment is the figure everyone plans around, and it is usually the largest regular cost of owning a home. It is not the only one. If the budget stops at the payment, the first few months can feel tighter than the affordability check suggested. This article sets out the other costs in the order they tend to arrive, how to put a figure on each, and how to track them.
Start with the payment, then test it
It is worth testing the payment against a higher rate in your own budget, since a rate rise is the change most likely to move the largest cost. Take a £300,000 repayment mortgage over 25 years. At 4.8% the monthly payment is £1,718.99. At 5.8% it is £1,896.39, which is £177.40 a month more (worked with the standard repayment formula, so check the figures against your own offer with the calculator).
If you are on a fixed rate, that gap does not hit you until the deal ends. If you are on a tracker or a variable rate, it can follow soon after a rate change. Either way, budget as though the higher figure is the real one, and treat any difference you do not spend as a cushion. The article on rate types explains how each type behaves when rates move.
Council tax
Council tax is billed by your local council on top of the mortgage. GOV.UK says the council sets the amount it charges for each band, so two homes in different areas with the same band can have different bills. A full bill is based on at least two adults living in the home, and a single adult can get 25% off, but you have to apply for the discount.
GOV.UK also says a property can be placed in a different band in some situations, for example if you alter it to create two or more self-contained units, and that you can ask the Valuation Office whether changes to your property will affect your band. If you are planning a conversion, ask before you commit to the work, and add any increase to your running costs.
Take the annual figure from your first bill and divide it by twelve for the budget.
Gas and electricity
Energy is the cost that moves most between homes and between seasons. Ofgem sets the price cap every three months, so the unit rate and standing charge you see on a bill from one quarter will not be the same in the next. Your own use matters more than the national figure: the number of people in the house, how well it is insulated, and the age of the boiler all change it.
Ofgem says that unless you have a smart meter or give regular readings, suppliers have to estimate your use, and on a standard variable tariff without a smart meter it suggests monthly readings. An estimate that runs low for months and then catches up in one bill is a common cause of budget shocks.
To find out where the electricity goes, a Ad plug-in energy monitor shows what an individual appliance draws, which helps you spot an old freezer or a tumble dryer that is costing more than expected. It measures appliances that plug into a socket, not the boiler or the heating system, so it answers part of the question and not all of it.
Water, broadband and insurance
These are fixed or near-fixed monthly costs. Water bills depend on whether the property has a meter. Broadband and mobile are contracts you may already hold and can move to the new address. Buildings insurance is a cost that your lender will tell you about if it requires cover, and the premium depends on the property, so get the figure before completion and put it in the budget.
Put each one in a list with the date it is due and the amount. Seeing the whole month in one place is what shows whether the payment dates bunch together.
The repairs fund
Houses wear. Boilers fail, roofs leak, and the gutter that looked fine at the survey needs replacing. There is no official figure for what to put aside each month, and any percentage rule is a rule of thumb rather than a fact, so work it from the property instead.
List the big items in the house with their approximate age: the boiler, the roof covering, the windows, the electrics and the kitchen. For each, estimate what a replacement would cost by getting a quote from a local firm. Divide the total by the years you expect each to last, and the result is a monthly figure that you can set aside in a separate pot.
Even a small regular transfer into a separate account means a repair is a withdrawal and not a crisis. An older home needs a larger pot than a new build, and a home with a flat roof or an old boiler needs more again.
Keeping it organised
Costs only stay in the budget if they are written down. A Ad household budget planner gives a page for each month, so you can see what was planned and what actually left the account. If you prefer to keep spending visible in cash, Ad budget envelopes with a cash wallet work for the categories you can cap, such as groceries.
Bills arrive by post as well as email, and the council tax, water and insurance papers pile up. An Ad expanding file with monthly dividers keeps them in one place. A Ad wall year planner shows the renewal and payment dates for the year at a glance, including the date your fixed rate ends.
A monthly running-costs list
Write these down with a figure against each, and total them next to the mortgage payment:
- Mortgage payment, plus a margin for a higher rate
- Council tax
- Gas and electricity
- Water
- Broadband and phones
- Buildings insurance, if required, and contents cover
- Repairs fund
- Any service charge or ground rent, if the property is leasehold
The total is the real monthly cost of the house, and it is the figure to compare with your take-home pay.