New legislation will cap payment terms, mandate interest and strengthen enforcement—reshaping UK payment practices and rebalancing power in supply chains.

Published: 13 May 2026
Author: Michelle Craven-Faulkner

Following on from our recent commentary on this topic the inclusion of the Small Business Protections (Late Payments) Bill in the King’s Speech signals a decisive shift in how payment practices will be regulated in the UK. Moving beyond incremental reform, the proposed regime introduces enforceable constraints on payment terms, backed by financial penalties and regulatory oversight.

For many businesses, the significance of the Bill lies not in the headline measures themselves, but in the operational and legal implications that follow: a fundamental recalibration of contracting models, cashflow management and dispute processes across supply chains.

From contractual freedom to statutory constraint

The proposed 60‑day cap on payment terms and mandatory statutory interest are well understood headline measures. Their real significance lies in the removal of commercial flexibility: payment terms will no longer operate as a negotiable lever, but as a regulated constraint with direct financial consequences.

Coupled with this is the move to make statutory interest on late payments mandatory and non-waivable, set at 8% above the Bank of England base rate. This is a subtle but important shift. The existing statutory framework has long permitted interest claims, but the ability to contract out of those rights has meant they are rarely exercised. By removing that discretion, the Government is effectively hard-wiring financial consequences into late payment itself.

In practice, this represents the emergence of a new form of economic regulation within B2B contracting. Payment behaviour—historically treated as a matter of commercial discretion—will instead be subject to oversight, enforcement and sanction.

Enforcement: From reputation to regulation

Historically, enforcement in this space has relied heavily on transparency and reputational pressure. The strengthened role of the Small Business Commissioner (SBC) marks a departure from that model. Under the proposed regime, the SBC will be equipped with powers to investigate, adjudicate disputes and, critically, impose substantial financial penalties on persistent offenders.

This is not merely an enhancement of an existing office; it represents the emergence of a new economic regulator in all but name. The implication for large corporates is clear: payment practices will no longer be an internal operational matter but a potential source of regulatory risk, with board-level visibility and consequence.

The proposed 30‑day deadline for raising invoice disputes reinforces this shift further. It targets a familiar tactical delay mechanism—late-stage disputes raised to defer payment—and replaces it with a more disciplined framework. In doing so, it pushes organisations toward tighter internal controls and faster decision-making around invoice validation.

Sectoral impact and supply chain dynamics

The impact will be particularly acute in those contractual environments where layered supply chains and milestone-based payments are common. In these sectors, the interaction between statutory payment obligations and existing contractual mechanisms (including retention and certification processes) is likely to generate both legal uncertainty and increased dispute risk.

More broadly, the reforms are likely to have a profound impact on supply chain dynamics. For SMEs, improved payment certainty should enhance liquidity, reduce reliance on external financing and support growth. For larger organisations, however, the cumulative effect—shorter payment cycles, mandatory interest exposure, and regulatory oversight—will require a fundamental recalibration of working capital management.

A cultural inflection point?

The central question is whether legislation can achieve what decades of voluntary codes and incremental reform have not: a genuine shift in payment culture. There are reasons to think this time may be different. The combination of hard legal obligations, financial penalties, and active enforcement creates a framework that is far more difficult to ignore.

That said, the success of the regime will depend on how it is implemented and enforced in practice. There will inevitably be areas of tension—particularly in complex supply chains where payment is linked to performance milestones or dispute resolution mechanisms. Careful drafting of secondary legislation and guidance will be critical to ensure that the regime is both robust and workable.

Looking ahead

For many organisations, the more immediate challenge will be operational:

• standard terms will require revision, particularly where extended payment periods are embedded across group contracts
• invoice validation processes must accelerate to meet compressed dispute windows
• working capital assumptions will need reassessment, particularly in sectors reliant on extended payment cycles
• governance and reporting structures may require uplift, given the increased visibility of payment practices.

The significance of the Small Business Protections Bill lies not simply in its individual measures, but in what it represents: a shift from a culture of negotiated payment practices to one of enforceable standards. For businesses, the key question is no longer whether payment terms are commercially acceptable, but whether they are legally sustainable in a more regulated environment.