So Green Tracker vs Octopus Tracker: what changes?

So Green Tracker and Octopus Tracker do not track the same thing. So Energy follows the Ofgem price cap (the regulator's limit on standard variable tariff prices) quarterly, while Octopus Tracker follows daily wholesale prices (what suppliers pay for energy). Both can change what you pay, but the speed of change, contract conditions and exposure to higher prices are different.

If you are choosing between the suppliers, compare the tariff you can actually join, not just the word 'Tracker'. A current quote, a previous year's bill and today's daily rate are three different pieces of information. None proves what either option will cost next year.

What does each tariff track?

Unit rates are the prices per kilowatt-hour and standing charges are daily connection fees. So Energy's Green Tracker page says both change with the Ofgem price cap every three months. It is not a tariff that passes on each day's wholesale movement directly. So Energy offers different contract lengths, so check the exact version in your quote.

Octopus Tracker uses a published formula linked to wholesale prices. There is one electricity unit rate for the day, and one gas unit rate if you take Tracker for gas. It is not Agile's half-hourly electricity pricing, and it is not an electric vehicle (EV) overnight discount.

That difference matters in both directions. Daily wholesale prices can fall before a quarterly cap-linked tariff changes, but they can also rise sooner. Slower price changes are not fixed prices, and faster changes are not guaranteed savings.

The Octopus Tracker guide explains the daily model and joining checks in more detail.

A contract term does not necessarily fix the unit rate

A fixed-length agreement is not, by itself, a promise of fixed energy prices. So Green Tracker has a contract term while its rates still move with the price cap. Its product page lists early-exit fees for the available terms. Check your own tariff documents before treating a variable-rate offer as something you can leave without cost.

Octopus describes Tracker as a 12-month fixed-term tariff because the pricing formula and standing charge are set for the term; the daily unit rates still change. Its Tracker FAQs say there is no exit fee. The smart-tariff terms separately say that leaving Tracker during the fixed term means waiting nine months before returning.

So compare both the cost of leaving and what you could join afterwards. No exit fee is not the same as an unrestricted return to the same tariff.

Compare the same home, then check the uncertainty

Use the same annual gas and electricity consumption, postcode and payment arrangement for both quotes. Include both standing charges if you use both fuels. Citizens Advice's tariff guide explains why the meter, budget and tariff structure matter alongside the unit rate.

So Energy's advertised saving against the price cap is not a promise that every household receives that amount, or evidence that its quote beats Octopus for your usage. Use the actual rates and standing charges in your offer.

For Octopus Tracker, last year's daily prices can help you understand past costs, but they cannot establish next year's bill. A single cheap day is even less useful. Check the applicable formula version, current regional prices and how much higher winter rates would affect your budget.

If you model a year using today's prices, label that assumption and consider what happens if prices rise. A cap-linked quote will also change at future cap reviews, so do not describe either variable option's annual estimate as a locked bill.

The postcode comparison tool helps with the Octopus side. It is not a live So Energy rate feed: obtain that quote directly from So Energy.

Which sort of price movement can you afford?

Octopus's Price Cap Protect is not the Ofgem default-tariff cap. Its own product page warns that the maximum daily Tracker rate can be much higher. If a period of unusually high prices would make essential energy unaffordable, do not choose Tracker on the hope that later cheap days will cancel it out.

So Green Tracker's quarterly cap link avoids daily wholesale repricing, but its rates can still rise at a cap change. A fixed-rate offer is a separate comparison if the priority is knowing the contracted unit rates. A fixed rate still does not fix the total bill: consumption matters.

For a new Octopus customer, the right comparison may therefore be So Green Tracker against Flexible or an available fixed quote, rather than assuming you must choose Octopus Tracker. Use the tariff-choice guide to narrow the options to a risk level and routine you can maintain.

Check the meter and the tariff start separately

Both suppliers' current Tracker pages require a suitable smart-meter arrangement. So Energy says it will arrange installation before moving a customer without a smart meter onto Green Tracker. Confirm availability for the actual property rather than treating that as an appointment or tariff-start guarantee.

Octopus says new customers normally join Flexible first, then complete the move to Tracker after it connects to the smart meter, receives the required readings and completes the tariff steps. Confirm the initial tariff and actual Tracker start date in your account. Do not count Tracker prices from the day the supplier switch begins unless Octopus confirms that is your tariff start.

Before you accept a switch

Keep the exact tariff name and version, contract length, fuel selection, rates, standing charges and exit conditions. Ask which prices can change, how you will be notified and which payment arrangement the quote includes.

Choose So Green Tracker if its actual cap-linked offer and conditions fit your home better. Consider Octopus Tracker only if the daily wholesale exposure, meter setup and return restrictions suit you. Neither supplier name makes the decision for you.

If a new Octopus signup still makes sense after those checks, the referral page explains the direct signup route. Existing Octopus customers comparing their next tariff should use their account options instead.