Running Costs Nobody Mentions to First-Time Buyers
You have budgeted for the deposit, the mortgage and the solicitor. Here are the household running costs that arrive afterwards, and how to avoid the default settings that quietly cost the most.
- Renting hid several costs from you. Owning surfaces them all at once.
- You inherit an energy tariff you never chose, on a deemed contract you can leave at any time.
- Council tax is your responsibility now, and registering late means a backdated bill.
- The expensive mistake is not choosing badly — it is choosing once and never reviewing.
Buying a first home means learning a long list of things nobody warned you about. Most first-time buyer guides stop at completion, which is exactly where the running costs start.
If you have been renting, several of these were previously somebody else’s problem, or were bundled invisibly into your rent. They are now yours.
What changes when you stop renting
| Cost | Renting | Owning |
|---|---|---|
| Energy | Often set up already, sometimes included | Yours from day one, on an inherited tariff |
| Council tax | Sometimes included in rent | Always your responsibility |
| Buildings insurance | Landlord’s problem | Yours, and normally required by the lender |
| Repairs | Landlord’s problem | Yours, including the boiler |
| Water | Sometimes included | Yours |
The energy tariff you did not choose
This is the one that catches most first-time buyers, because it is invisible.
When you complete, you become a customer of whichever supplier already serves the property. Not by choice — by default. You are placed on what is called a deemed contract, usually the supplier’s standard variable tariff, which is rarely their most competitive rate.
The important part: you are not bound by anything the previous owner signed. Their fixed deal, their remaining term, their exit fees — none of it transfers. You can switch whenever you like with no exit fee, because you never agreed to a term.
Do this on day one: photograph the gas and electricity meters with the serial numbers visible, then contact the supplier within a few days with your name, move-in date and readings. Until you do, estimated charges accumulate against the property — and disputing an estimate nobody recorded rarely ends in your favour.
Council tax
Contact the local authority as soon as you move in. This is easy to forget in the chaos of the first week, and forgetting generates a backdated bill rather than a waived one.
If you are the only adult in the property, you may be entitled to a single-person discount. Check the band the property is in as well — bands are public information and worth knowing before you budget.
Broadband: the one with a deadline
Every other item on this list can be sorted after you move in. Broadband cannot.
A new installation typically takes two to six weeks, and considerably longer on a new-build development that has not yet been connected. If you leave it until moving week, you may spend your first month in the house without a connection.
Start this four to six weeks before completion, and check availability at the exact postcode rather than assuming your current package will follow you.
Budget for the boiler
Nobody enjoys this advice, but the boiler is now yours. If the survey flagged its age, build a repair fund from the start rather than discovering the problem in January.
The mistake that actually costs money
It is not choosing slightly the wrong provider. It is choosing once, in the chaos of moving week, and never looking again.
Default tariffs are where you end up if you do nothing, and they are not designed to be competitive. A household that reviews everything once a year will generally do better than one that made a theoretically optimal choice at completion and has not touched it since.
Set a reminder for eleven months after you move. That is the single most useful thing you can do with this article.
Frequently asked questions
Am I stuck with the previous owner’s energy supplier?
No. You are placed with them by default on a deemed contract, but you can switch at any time with no exit fee, because you never agreed to a contract term.
When should I register for council tax?
As soon as you move in. Registering late does not avoid the charge — it produces a backdated bill instead.
What should I sort first as a first-time buyer?
Broadband, because it has by far the longest lead time. Energy and council tax can be arranged in the days after you move in; broadband may need weeks of notice.
Want a hand with the running costs?
Book a free 15-minute household-services review covering energy, broadband and mobile for your new home. Free, online, and no obligation to take anything.
Official sources
- GOV.UK: Council tax
- Ofgem: Get energy if you are moving home
- Citizens Advice: Moving home and your energy supply
- Ofcom: Broadband and mobile checker
This guide provides general information, not regulated financial advice. Costs, eligibility and contract terms vary. Quantome Commerce Limited operates as an independent authorised partner of a UK multi-service provider and may receive commission if you choose eligible services following an introduction.