2.1 Sterling as Primary Currency

What currency would an independent Scotland use?

The core question is one of the highest-stakes decisions in any independence transition: what currency would an independent Scotland use? The short answer is continuity. An independent Scotland would continue to use the pound sterling as its primary currency from Independence Day. This is the least disruptive option for wages, prices, savings, mortgages, contracts and day-to-day transactions. It avoids the immediate risks of launching a new currency while fiscal credibility and institutions are still being established.

Currency is one of the highest-stakes decisions in any independence transition. The wrong choice, or a poorly timed change, can generate immediate instability in prices, debt burdens and public confidence. Virtually every Scottish wage, price, mortgage, savings account, pension and commercial contract is already denominated in sterling. Continuing to use it avoids widespread conversion, repricing, or renegotiation at the precise moment when debt settlement, institution-building, and international recognition are also underway. The decision prioritises continuity and stability over monetary symbolism. It is consistent with the broader approach of this framework: minimise avoidable disruption on day one, build institutions and credibility, and only then consider further change.

The main trade-off is clear and is not hidden. Sterlingisation means no independent Scottish monetary policy and no automatic access to the Bank of England as lender of last resort. Interest rates remain set for the sterling area as a whole. Those constraints are real. They are accepted at the outset because the alternative—immediately introducing a new currency—is judged to carry greater near-term risk to living standards and financial stability. The constraints are managed through fiscal rules, a Scottish Central Bank focused on financial stability, bank regulation, deposit protection and reserves, as set out in the following sections of this part. The negotiation red line on continued use of sterling, the continuity of contracts and pensions, and the 18–24 month working timeline all presuppose a clear currency choice that can support ordinary economic life from the first day of independence. Precision about what sterlingisation delivers, what it does not deliver, and how the accompanying institutions would make it workable is therefore essential to credibility with households, businesses, markets and counterparties.

Current Position and Legal/Institutional Baseline

Sterling is already the unit of account, the medium of exchange and store of value for the Scottish economy in ordinary use. Households think, budget and borrow in sterling. Firms price and contract in sterling, especially for the dominant rest-of-UK market. Banks, pension schemes and payment systems operate in sterling. The Bank of England sets monetary policy for the sterling area as a whole. There is no separate Scottish monetary authority and no separate Scottish currency in circulation as legal tender. The existing legal and institutional baseline is therefore one of complete integration into the sterling system for private and most public transactions.

Independence does not, by itself, extinguish people's and businesses' ability to continue using sterling. Unilateral use of another state’s currency—sterlingisation—is legally possible without a formal currency union and without UK permission for ordinary private use. Sterling is a fully convertible currency. Scottish residents and firms already hold, earn, spend and borrow it. The policy choice is therefore not whether sterling can be used, but whether the state should prioritise continuity of the existing unit or prioritise early monetary independence. Successive UK governments have ruled out formal currency union with the rest of the UK—shared institutions, shared monetary policy, and a formal lender-of-last-resort arrangement—and this framework does not seek it. It would require joint decision-making incompatible with Holyrood's goal of full policy control. The baseline after a lawful Yes vote is therefore a choice between continued unilateral use of sterling under a domestic institutional framework designed for stability, or the immediate launch of a new Scottish currency. This framework selects the former for the transition and the early years of independence.

Mechanism and Delivery

The mechanism is the unilateral use of sterling as the primary currency from Independence Day, supported by a domestic institutional framework that manages the regime's constraints. No new currency needs to be printed or introduced. No UK licence is required for private transactions in sterling. Wages and salaries continue to be paid in the same currency. Prices in shops and contracts remain in sterling without forced conversion. Existing mortgages, loans and savings accounts continue on their current terms. Businesses that trade across the border with the rest of the UK face no new currency transaction costs or exchange-rate risk on their dominant market. Pensions and benefits already denominated in sterling continue without currency conversion issues.

The focus would be on building the institutional framework for continued use. A Scottish Central Bank would be established with a mandate focused on financial stability and prudential regulation rather than on setting interest rates under sterlingisation. Legislated fiscal rules and an independent fiscal institution would support credibility when monetary policy remains external. Bank regulation and capital and liquidity standards would be set at levels appropriate to a sterlingised system. A deposit protection scheme with a clear fiscal backstop would protect depositors. A reserves strategy would provide a buffer for liquidity and confidence management. The following sections of this part and the fiscal sections of the wider framework address these supporting arrangements. Sterlingisation without them would be fragile. Sterlingisation with them is a constrained but workable regime.

In practice, technical cooperation on payment systems and information-sharing would be sought. If cooperation is limited, sterlingisation still proceeds as unilateral use; the cost is higher reliance on domestic reserves, capital and liquidity standards, and fiscal backstops. The red line on sterling, set out in the negotiation principles, is non-obstruction of ordinary use and a shared interest in avoiding gratuitous financial disruption—not a demand that the Bank of England underwrite Scotland’s system. A path to a possible future Scottish currency is retained, subject to strict, pre-published tests of fiscal sustainability, reserves, central bank capacity and banking stability. A later section addresses that path. It is not the day-one policy.

Continuity Design

Currency continuity is a design requirement that protects wages, prices, savings, mortgages, contracts and pensions. Existing financial contracts denominated in sterling remain enforceable under continuing Scots law without conversion or renegotiation. Household balance sheets face no forced currency shock. Businesses that price and invoice in sterling for the rest-of-UK market face no new transaction costs or exchange-rate exposure on that dominant trade. Payment systems that already operate in sterling continue. Accrued pension rights denominated in sterling continue without currency conversion issues. The default is continuity of the unit in which ordinary economic life is conducted. Any later move to a Scottish currency would be a managed change under pre-published tests, not an emergency response to crisis.

Currency continuity aligns with continuity of law, contracts, Parliament, Government and rights. It reduces one of the most immediate sources of anxiety for households and firms at the moment of constitutional change. It supports the negotiation red line on sterling and the wider continuity-first approach to pensions, benefits and public services. Sterlingisation is not a minor technical preference; it is a household and commercial stability measure that keeps the unit of account constant while institutions and credibility are built.

Constraints and Trade-offs

Legal constraints

Unilateral use of sterling for private transactions requires no UK permission and no formal currency union. The legal constraint is limited. Domestic legislation is required to establish the Scottish Central Bank, the fiscal rules, the deposit protection scheme, and the regulatory framework that makes the regime stable. Treaty or intergovernmental arrangements may be relevant to technical cooperation on payment systems, but they are not a condition of ordinary use. The legal constraint is therefore the need for clear domestic statutory foundations for the supporting institutions, not any prohibition on using sterling itself.

Fiscal constraints

Sterlingisation does not impose a direct “currency launch” cost. It does require funding the Scottish Central Bank, designing the deposit protection scheme and its potential fiscal backstop, and accumulating reserves. Those costs sit inside the transition and the medium-term fiscal plan. They are real. They are smaller and more controllable than the balance-sheet and confidence costs of a poorly prepared new currency at the moment of independence. The opening fiscal deficit remains the central fiscal challenge; sterlingisation does not solve it and does not pretend to. It avoids adding a monetary shock on top of it. The fiscal rules and independent fiscal institution are therefore essential companions to the currency choice: they must carry credibility when monetary policy is external.

Operational constraints

Operational delivery requires payment systems to continue functioning in sterling, banks to meet appropriate capital and liquidity standards, deposit protection to be credible, and the Scottish Central Bank to be ready to perform its stability and regulatory functions. The UK would seek technical cooperation on payment infrastructure; if limited, it would require greater domestic resilience. The operational constraint is building the supporting institutional capacity within the 18–24 month timeline while ordinary sterling transactions continue without interruption. Early clarity that sterling continues, strong prudential standards and a visible central bank mandate for stability are the design response. Declaring a new currency under crisis pressure is not the contingency plan.

Political constraints

Political pressure for an immediate Scottish currency, or for a formal currency union already refused, is foreseeable. Critics may argue that sterlingisation is a form of incomplete independence or that it leaves Scotland exposed to policy set elsewhere. The political constraint is maintaining the integrity of the continuity choice against maximalist demands for early monetary divergence. The response is that, in the transition period, stability of wages, prices, savings and contracts takes priority; that the constraints of sterlingisation are acknowledged and managed through domestic institutions; and that a conditional path to a future Scottish currency is retained under strict tests. Credibility depends on refusing both the assumption that a new currency would be ready on day one and the pretence that sterlingisation is unconstrained.

Time constraints

The currency choice itself—continued use of sterling—requires no implementation period beyond the legal and institutional preparation of the supporting framework. That preparation sits inside the 18–24 month working timeline. Reserves accumulation, central bank readiness, deposit protection design and fiscal rules must be advanced sufficiently by Independence Day to support confidence. The time constraint is therefore the institutional build around the currency choice rather than the choice itself. A later move to a Scottish currency would be subject to pre-published tests and would not be forced by an artificial deadline. Competence in the supporting arrangements takes priority over symbolic speed.

Consistency with the Wider Framework

Sterling as primary currency is a negotiation red line and a monetary design choice. It aligns with continuity of contracts, mortgages, savings and pensions; with the priority of the rest-of-UK market and light-touch borders under an enhanced Common Travel Area-style arrangement; and with fiscal rules and an independent fiscal institution that must carry credibility when monetary policy is external. It frames the Scottish Central Bank's role as focused on financial stability and prudential regulation rather than interest-rate setting under sterlingisation. It frames the lender-of-last-resort constraint, deposit protection, reserves and the conditional path to a future Scottish currency. There is no tension with the constitutional continuity sections: the same continuity-first logic applies to the unit of account as to law, Parliament, rights and the courts.

The currency choice supports the wider continuity of living standards and commercial relationships at the moment of maximum institutional stress. It does not resolve the opening fiscal position; the fiscal rules and institutional design address that challenge. It does not provide independent monetary policy; it accepts and manages that constraint. It does not create automatic access to Bank of England liquidity facilities; domestic reserves, regulation and fiscal backstops are the response. The framework treats sterlingisation as a constrained but workable regime for the transition and early years, with a later option for monetary evolution if and when evidence supports it. That sequencing matches the prospectus's continuity-first design.

Hardest Critiques and Direct Responses

Feasibility

The hardest practical critique is that Scotland cannot “keep the pound” without UK permission, or that sterlingisation is unstable by definition without formal currency union and lender-of-last-resort access. The response is direct. Unilateral use of sterling is legally possible and already describes ordinary private behaviour. Formal currency union is not required and is not sought. Stability under sterlingisation depends on fiscal rules, bank regulation, deposit protection and reserves—which this framework treats as mandatory accompanying policy, not as optional extras. Feasibility of the currency choice itself is high. Feasibility of sterlingisation as a stable regime depends on delivering the supporting institutions within the transition timeline. Critics who prefer an immediate Scottish currency must still explain how credibility, reserves and institutions would be ready on day one. This framework declines to assume they would be.

Cost and fiscal burden

Critics will argue that the costs of a Scottish Central Bank, deposit protection backstop and reserves accumulation impose an unnecessary burden on top of the opening fiscal deficit. The response is that these costs are real, sit inside the transition and medium-term fiscal plan, and are smaller and more controllable than the balance-sheet and confidence costs of a poorly prepared new currency at independence. Sterlingisation does not solve the opening fiscal challenge and does not pretend to. It avoids adding a monetary shock on top of it. The fiscal rules and independent fiscal institution are designed to support credibility under external monetary policy. Under-funding the supporting institutions would make the regime fragile; that is a policy failure, not an inherent defect of the currency choice.

Dependence on agreement

Dependence on the UK is limited. A formal currency union is not sought and has been refused. Lender-of-last-resort access from the Bank of England is not automatic and is not treated as a right. Technical cooperation on payment systems would be sought as a practical matter. If cooperation is limited, sterlingisation still proceeds as unilateral use; the cost is higher reliance on domestic reserves, capital and liquidity standards, and fiscal backstops. The red line is non-obstruction of ordinary use and a shared interest in avoiding gratuitous financial disruption. The response is that the currency choice does not depend on UK permission for private use, and that the supporting domestic institutions are designed to operate with or without full technical cooperation.

Transition risk

The main continuity risks under sterlingisation are bank liquidity stress, deposit flight under uncertainty, and weak fiscal credibility feeding financial instability. Mitigation is early clarity that sterling continues, strong deposit protection, high prudential standards, published fiscal rules and a visible central bank mandate for stability. Declaring a new currency under crisis pressure is not the contingency plan; the contingency plan is reserves, regulation, and fiscal discipline within sterlingisation, with a later currency option only when tests are met. Transition risk is minimised by continuity of the unit of account and maximised by an unprepared monetary experiment at the moment of maximum institutional stress. The framework chooses the lower-risk path.

Alternatives (status quo and previous proposals)

Successive UK governments have ruled out a formal currency union and do not seek it; it would require joint decision-making incompatible with full policy control. Introducing a new Scottish currency on Independence Day is possible in principle but carries significant short-term risks to prices, debt burdens, and confidence while fiscal institutions, debt arrangements, and recognition are still being settled; that alternative is deferred until strict tests are met. The status quo of sterling use inside the United Kingdom ends with independence in its current institutional form; the framework replaces it with unilateral sterlingisation under a domestic stability framework. Previous prospectus material that left currency options more open or that prioritised early monetary independence is deliberately set aside in favour of continuity first. The constraints of sterlingisation are acknowledged and managed, not denied or deferred.

Political and public credibility

The claim most likely to be called unrealistic is that sterlingisation can deliver stability without independent monetary policy or automatic lender-of-last-resort support. The precise answer is that the constraints are real and are accepted because stability of wages, prices, savings and contracts takes priority in the transition period. The supporting institutions—fiscal rules, the Scottish Central Bank focused on stability, bank regulation, deposit protection and reserves—are treated as mandatory. Credibility with households, businesses and markets depends on early clarity about the currency choice, on the visible build of the supporting framework, and on honesty about what the regime does and does not provide. A strategy that promised unconstrained monetary independence on day one without the institutions to support a new currency would forfeit that credibility. A strategy that treated sterlingisation as costless would do the same. The framework states the choice, the constraints and the management of those constraints with equal clarity.

Position Summarised

Scotland would continue to use the pound sterling as its primary currency from Independence Day. This is the least disruptive choice for households, businesses and the financial system. It avoids the immediate risks of launching a new currency while fiscal credibility and institutions are still being built. The loss of independent monetary policy and of automatic Bank of England lender-of-last-resort access is a real constraint and is acknowledged as such. It is accepted because stability and continuity for wages, prices, savings and contracts take priority in the transition period. Constraints are managed through fiscal rules, a Scottish Central Bank focused on financial stability, bank regulation, deposit protection and reserves. Any future move to a Scottish currency would occur only once clear readiness tests are met. Continuity first; monetary evolution later, if and when the conditions justify it. Ordinary use of sterling requires no UK licence for private transactions. The institutional framework that makes the regime stable is a domestic responsibility and a design requirement of this prospectus.

Conclusion

The currency of an independent Scotland on day one would be sterling. That choice protects the unit in which people are paid, save, borrow and price goods, and it avoids a monetary experiment at the moment of maximum institutional stress. Formal currency union is not available and is not sought. A new Scottish currency is deferred until strict tests of fiscal sustainability, reserves, central bank capacity and banking stability are met. Sterlingisation is a constrained regime. This framework does not deny the constraints. It builds the domestic institutions and rules that make the regime workable, and it keeps a conditional path to monetary evolution if and when evidence supports it. Currency continuity is the monetary counterpart of continuity of law, Parliament, pensions and contracts. Taken together, they define a transition that prioritises the stability of ordinary economic life over symbolic change on day one. Every subsequent section of this part—on the Scottish Central Bank, fiscal rules, deposit protection, reserves and the conditional path to a future currency—presupposes this day-one choice and the constraints it accepts. This section states the choice, the reasons for it, and the institutional framework required to make it stable.

Series Footer

This analysis forms part of People’s Future Scotland: The Independence Debate, a series examining the practical, legal and institutional questions that would arise in any move to independence. Each section is designed to withstand scrutiny by setting out mechanisms, constraints and continuity requirements with equal clarity. The series proceeds from the premise that a decision of this magnitude requires a process and a prospectus that both supporters and opponents can recognise as serious.