Business Energy Debt Block UK: When a Switch Is Held Up by Outstanding Debt

What a Debt Block Is and How It Operates

A debt block is a flag placed on an electricity or gas supply point that prevents the switching process from completing. When a business initiates a switch to a new supplier, the new supplier submits a switch request through the relevant industry switching infrastructure. The outgoing supplier is notified and has the right to raise an objection if a qualifying debt exists. Where a valid objection is raised, the switch is held and the business remains on supply with the current supplier until the block is resolved.

For electricity, the switching process operates under the Master Registration Agreement (MRA), a multi-party industry agreement that governs the processes for registering, transferring, and managing electricity supply points. The MRA sets out the conditions under which a supplier can raise a valid switching objection, including the debt thresholds and notice requirements. Ofgem oversees the MRA framework and publishes guidance on its obligations for suppliers.

For gas, the equivalent framework is the Uniform Network Code (UNC), which governs gas transportation and associated processes including supply point switching. The UNC debt objection provisions broadly mirror the electricity framework, requiring that a debt meets defined criteria before a valid objection can be raised against a switch.

Financial Thresholds and What Counts as Qualifying Debt

Under the industry codes, a debt block can only be raised where the outstanding balance meets the relevant financial threshold. Ofgem publishes guidance on the applicable thresholds and the conditions for valid debt objections. Suppliers are not permitted to raise a switching objection for trivial balances or for amounts that fall below the qualifying threshold.

Qualifying debt for switching objection purposes means an undisputed amount that has been formally invoiced, is past due, and has not been subject to a payment arrangement that is being honoured. The key word is undisputed: a balance that the customer has formally contested under the supplier's complaints process is not eligible to be treated as a valid debt grounds for a switching block while the dispute remains unresolved.

Common situations where suppliers incorrectly raise blocks include: estimated bills that are higher than actual consumption; wrong tariff applied to the account; billing for a period covered by a previous tenant; and administrative errors resulting in duplicate or incorrect charges. In each case, the customer should formally dispute the charge before the switch is initiated, as this places the amount into the disputed category and removes it from the valid grounds for a block.

The Obligation on the Losing Supplier

When a supplier raises a switching objection, it is making a formal representation that a qualifying debt exists. The supplier is obliged under the industry code provisions and Ofgem's licence conditions to be able to substantiate that representation. An objection raised on invalid grounds, including in respect of a disputed amount or an amount below the qualifying threshold, is a breach of the supplier's obligations.

Ofgem's licence conditions require suppliers to handle switching objections accurately and only where the conditions for a valid objection are met. A supplier that raises a block knowing the underlying amount is disputed, or that cannot substantiate the debt on request, may be in breach of its licence. This is relevant both to any direct challenge to the supplier and to any subsequent Ofgem complaint.

The losing supplier must also respond to the switching process within the timeframes prescribed by the MRA or UNC. Failing to object within the prescribed window means the switch proceeds regardless of any debt, though the debt obligation itself is not extinguished by the switch completing.

How to Lift a Debt Block

There are four principal routes to lifting a debt block, and the appropriate route depends on the circumstances.

Clearing the debt: The most straightforward resolution is paying the outstanding balance in full, assuming the amount is not disputed and the customer has the funds available. On receipt of cleared payment, the supplier is obliged to withdraw the switching objection promptly.

Agreeing a payment arrangement: Where full payment is not immediately possible, a formal payment plan agreed with the supplier may resolve the block. Under Ofgem's licence conditions, suppliers are required to offer payment arrangements to customers in financial difficulty. Once a payment arrangement is in place and being honoured, the basis for the switching objection may no longer be valid depending on the specific code provisions applicable to the supply point type.

Raising a formal dispute: Where the debt is contested, the customer should raise a formal complaint with the supplier under its published complaints procedure. Once the amount is in formal dispute, it should not be treated as qualifying debt for switching objection purposes. If the supplier continues to maintain the block against a formally disputed amount, this is escalatable to the Energy Ombudsman as a complaint about the switching objection itself.

Debt Assignment Protocol: The Debt Assignment Protocol (DAP) is an industry arrangement that allows a customer's debt to be transferred to the new supplier as part of the switching process, so that the switch completes and the debt is then owed to the new supplier rather than the old one. Not all suppliers participate in the DAP, and it is more commonly used in the domestic market than the business market, but its availability should be explored with the new supplier as an option where the debt is acknowledged and switching is the priority.

The Energy Ombudsman and Improperly Applied Blocks

The Energy Ombudsman can consider complaints about switching objections that have been improperly raised, for qualifying business customers. Since December 2024, eligibility covers both Ofgem-defined microbusinesses (under SLC 7A) and a new small business category (fewer than 50 employees, turnover below £6.5 million or balance sheet below £5.0 million, and consumption below the specified thresholds). Where a supplier has raised a block against a disputed amount, failed to withdraw a block after the debt has been cleared, or applied a block for an amount below the qualifying threshold, the Ombudsman can investigate and require the supplier to take corrective action.

Remedies the Ombudsman can direct in a switching objection dispute include requiring the supplier to withdraw the objection, directing a refund where the block was based on an overcharged amount, and awarding compensation for the period of delay caused by the improper block. The Ombudsman's decisions are binding on the supplier for businesses within its jurisdiction.

Before escalating to the Ombudsman, the customer must have raised a formal complaint with the supplier and either received a final response or allowed eight weeks without resolution. This prerequisite applies regardless of how clear-cut the objection appears to be. Keeping records of all communications about the switch request and the objection is essential for an Ombudsman referral.

Practical Steps on Discovering a Block Has Been Raised

When a switch fails to complete within the expected timeframe, the new supplier should be contacted to confirm whether a switching objection has been raised and by which supplier. The new supplier should be able to identify the basis of the objection. The outgoing supplier should then be contacted in writing to request a written explanation of the debt amount claimed, the period it covers, and the tariff applied.

If the amount is recognised and undisputed, the fastest resolution is payment or a payment arrangement. If the amount is disputed, a formal complaint should be submitted to the outgoing supplier in writing immediately, specifying that the block is being treated as improperly applied to a disputed amount. All correspondence should be dated and retained.

Frequently asked questions

Editorial disclaimer: The following questions address common points of uncertainty about debt blocks and business energy switching. They do not constitute legal or financial advice. Businesses in a dispute with their supplier should seek independent advice appropriate to their circumstances.

Can a supplier block my switch for a disputed invoice?

A disputed amount should not be treated as valid grounds for a switching objection under the industry codes. Once an amount has been formally contested through the supplier's complaints process, it is in dispute and the supplier should not raise or maintain a switching block on the basis of that amount. If a supplier maintains a block against a formally disputed amount, this is escalatable to the Energy Ombudsman as a breach of switching obligations.

How long does a supplier have to raise a switching objection?

The MRA and UNC specify prescribed timeframes within which a supplier must raise a valid objection after receiving a switch notification. Failing to raise an objection within the prescribed window means the switch proceeds. The specific timescales are defined in the relevant industry code and vary by supply point type. Your new supplier should be able to confirm the applicable timescale for your specific switch.

What is the Debt Assignment Protocol?

The Debt Assignment Protocol is an industry arrangement that allows a customer's qualifying debt to transfer to the new supplier as part of the switching process, rather than blocking the switch. This means the switch completes and the debt obligation moves to the new supplier. The DAP is not universally available and participation varies by supplier. It is more common in the domestic market, but businesses should ask the new supplier directly whether DAP is available for their switch.

Can the Energy Ombudsman help if my switch is being blocked unfairly?

Yes, for qualifying microbusinesses. The Energy Ombudsman can investigate complaints about improperly raised switching objections and can direct the supplier to withdraw a block, issue a refund for overcharged amounts underlying the block, and pay compensation for switching delays caused by the improper objection. The formal complaint must first be raised with the supplier, and either a final response received or eight weeks elapsed without resolution, before the Ombudsman can accept a referral.

If I pay the blocked debt and switch, do I lose the right to dispute the amount?

Paying a disputed amount to lift a block does not automatically waive the right to seek a refund if the amount is later found to be incorrectly charged. A formal complaint about the underlying billing dispute can continue in parallel with or following the switch. Paying under protest should be documented explicitly in writing to the supplier at the time of payment, stating that payment is made to facilitate the switch and does not constitute acceptance of the amount claimed.

How we verified this

This article draws on Ofgem's published guidance on the switching process and supplier objection obligations, the Master Registration Agreement framework as referenced in Ofgem's electricity retail market documentation, Citizens Advice guidance on business energy debt and switching, and the Energy Ombudsman's published guidance on switching complaints. The Debt Assignment Protocol is referenced in publicly available Ofgem and Energy UK industry documentation.

Sources

• Ofgem - Switching and supplier objection guidance
• Citizens Advice - Switching and debt blocks
• Ofgem - Supplier licence conditions on switching
• Energy Ombudsman - Switching complaints guidance

For related reading on switching and debt management, see Business Energy Switching Process UK and Business Energy Payment Plan UK.