How to Create a Custom Tariff: Standard, Economy 7 and Time of Use

Most of the tariffs you compare on Heat Pump Tariffs come straight from our database. But there are times when you need one that isn't there: you're on a deal that's too new or too niche to be listed, you've negotiated something bespoke, or you simply want to model a hypothetical rate before committing to a switch.

That's what custom tariffs are for. They're private to your account, they sit alongside the supplier tariffs in your comparison results, and you can create as many as you like. This guide walks through all three types — Standard, Economy 7 and Time of Use — with a worked example and the common mistakes to avoid for each.

Before you start

Head to My Custom Tariffs and click Add Custom Tariff. Every tariff, whatever its type, shares the same opening fields:

• Supplier — pick a listed supplier from the dropdown, or leave it on "— Custom / Unlisted Supplier —" and type a name in the Custom Supplier Name box that appears.
• Tariff Name — required. Give it something you'll recognise later, like "My Fixed Rate Deal".
• Type — Standard, Economy 7 or Time of Use. This is the important one: it changes which rate fields appear below.
• Contract Type — Variable or Fixed (cosmetic; it doesn't change the maths).
• Contract End Date — optional, handy if you're tracking a fixed deal.
• Standing Charge (p/day) — the daily charge in pence, e.g. 53.35.
• VAT included in rates — leave this on if your rates already include VAT, which is almost always the case for the prices a supplier quotes you.

Below that, the Rates card has two dates that apply to all types:

• Effective From — when this rate starts. Defaults to today.
• Effective To — leave blank to mean "currently active". If you enter your rates and then later edit them with a new Effective From date, the old version is automatically closed off the day before — so your history stays intact.

With those covered, let's look at each type.

Standard tariff

What it is

A Standard tariff is the simplest kind: one flat unit rate for every kilowatt-hour, at any time of day, plus the daily standing charge. If your bill shows a single p/kWh figure, this is you.

How to create it

1. Set Type to Standard.
2. Fill in the Standing Charge and the shared fields above.
3. In the Rates card, enter your Unit Rate (p/kWh) — for example 24.5.
4. Click Save Custom Tariff.

Worked example

Say you're on a flat-rate deal at 24.5p per unit with a 53.35p daily standing charge:

• Standing Charge: 53.35
• Unit Rate: 24.5

That's it. The comparison engine applies that 24.5p to every half-hour of your smart meter data.

Common mistakes

• Entering pounds instead of pence. The unit rate field expects pence per kWh. 0.245 is a quarter of a penny — you want 24.5.
• Forgetting the standing charge. Leaving it blank treats the tariff as having no daily charge, which flatters it unfairly against rivals that do.

Economy 7 tariff

What it is

Economy 7 splits the day into two rates: a cheaper night rate over a fixed window (typically seven hours overnight, hence the name) and a higher day rate the rest of the time. It suits households that can shift heavy use — heat pump heating, hot water, EV charging — into the night window.

How to create it

1. Set Type to Economy 7. The rate fields change to show day and night inputs.
2. Enter your Day Rate (p/kWh) and Night Rate (p/kWh).
3. Set the Night Start and Night End times. These are the boundaries of your cheap window — check your supplier's exact times, as they vary.
4. Add the Standing Charge and save.

Worked example

A typical Economy 7 setup with a midnight-to-7am night window:

• Day Rate: 28.5
• Night Rate: 14.2
• Night Start: 00:00
• Night End: 07:00
• Standing Charge: 53.35

Any consumption recorded between midnight and 7am is billed at 14.2p; everything else at 28.5p.

Common mistakes

• Using the wrong night window. Economy 7 times differ by supplier and even by meter — some run 23:30–06:30, others 00:30–07:30. If your window is off by an hour, your savings estimate will be too. Confirm the times with your supplier before entering them.
• Assuming the night rate always wins. Economy 7 only pays off if enough of your usage falls in the cheap window. If most of your consumption is during the day, the higher day rate can make it worse than a good Standard tariff — which is exactly the kind of thing a comparison will reveal.

Time of Use (TOU) tariff

What it is

A Time of Use tariff divides the day into multiple priced bands — for example a cheap overnight rate, a standard daytime rate, and an expensive peak band in the early evening. It's the most flexible type and the closest match to modern smart tariffs.

How to create it

1. Set Type to Time of Use. A Rate Bands section appears.
2. Click Add Band for each period you want to define. Each band has:
   • Name (e.g. "Off-Peak", "Day", "Peak")
   • Start and End times
   • Rate (p/kWh)
3. Keep adding bands until the coverage bar under the table reads 100% covered. Your bands must account for all 24 hours — the form won't save with gaps.
4. Add the Standing Charge and save.

Worked example

A three-band tariff with a cheap night, a standard day, and a costly evening peak:

Those four bands run end-to-end with no gaps, so the coverage bar hits 100% and the tariff saves cleanly.

Common mistakes

• Leaving a gap in coverage. This is the big one. If your bands don't cover every half-hour of the day, the coverage bar stays below 100% and the form refuses to save. Make each band's End time match the next band's Start time, and make sure the final band wraps back round to where the first one began.
• Overlapping bands. The form accepts overlapping bands, but a slot covered twice can produce surprising results. Keep your start and end times flush, not overlapping.
• Too many bands. There's a ceiling of 48 bands (one per half-hour). You'll almost never need more than a handful.

What happens after you save

Your custom tariff appears in the My Custom Tariffs list, where you can edit or delete it any time. More importantly, it's now part of your comparisons — run a comparison from your dashboard and you'll see your custom tariff ranked against every supplier tariff for your region, scored against your actual smart meter usage.

That's the real payoff: instead of guessing whether a deal is good, you can see exactly what it would have cost you over the period you've already lived through.