The pound does not have one “correct” forecast. GBP/USD and GBP/EUR are relative prices: sterling can strengthen because the UK outlook improves, because the US or euro-area outlook deteriorates, or because markets change their view of the interest-rate gap between the two economies.
That is why a useful sterling outlook is a framework rather than a point target. In September 2026 the main UK variables are Bank Rate, inflation, growth, fiscal expectations and the external balance. The Bank of England's current Bank Rate is 3.75%, with the next Monetary Policy Committee decision due on 17 September 2026.
1. Relative interest rates are the first thing to watch
Currencies respond to expected returns, not only today's policy rate. If markets come to expect UK rates to stay higher than comparable US or euro-area rates, sterling can become more attractive at the margin. If expected UK rates fall faster, the reverse can happen.
The Bank of England's July 2026 Market Participants Survey showed a median expectation of Bank Rate remaining at 3.75% through the end of 2026 and into early 2027. That is a survey of market participants, not a promise from the MPC, but it provides a useful snapshot of the rate path investors were assigning most weight to before the September meeting.
The key word is relative. A UK rate cut does not automatically mean a weaker pound if the Federal Reserve or European Central Bank is expected to ease more aggressively at the same time.
2. Inflation matters through the policy reaction
Higher UK inflation can support sterling if markets think it will force the Bank to keep rates higher. But persistent inflation is not unambiguously positive for a currency: if it damages real growth or undermines confidence, the growth and credibility effects can outweigh the rate effect.
The latest published ONS CPI release is for July 2026, when CPI inflation was 2.9%. The next inflation release is due on 16 September, one day before the MPC decision. That sequencing makes the September inflation print unusually relevant to short-term sterling pricing.
For the broader inflation path, see Briefed's UK inflation outlook.
3. Growth changes the expected return on UK assets
Stronger growth can support the pound through several channels: higher expected corporate earnings, stronger tax receipts, a less dovish Bank of England path and greater demand for UK assets. Weak growth can do the opposite.
The important distinction is between a one-month GDP print and a durable change in the outlook. Sterling is a forward-looking asset price. A surprise matters most when it changes expectations for the next several quarters rather than merely revising the recent past.
For the current domestic growth picture, see the UK growth tracker and UK GDP per capita.
4. Fiscal credibility and gilt yields can move sterling together
Fiscal policy matters when it changes expected borrowing, growth, inflation or the risk premium investors demand to hold sterling assets. A rise in gilt yields is therefore not automatically bullish for the pound. Yields can rise because expected policy rates are higher, which may support sterling, or because investors demand more compensation for fiscal or inflation risk, which may be a much less constructive signal.
That distinction is especially relevant ahead of the 28 October 2026 Budget. For the fiscal-rule backdrop, see UK fiscal headroom in 2026. For the bond-market mechanics, see why UK gilt yields matter.
5. The UK's external balance is the slower-moving constraint
The UK runs a current-account deficit, meaning the country as a whole spends more abroad than it receives through trade and income flows and therefore relies on net external financing. In the first quarter of 2026, the ONS estimated the underlying current-account deficit excluding precious metals at £15.1 billion, or 1.9% of GDP.
A current-account deficit does not mechanically weaken sterling. The UK has deep capital markets and can attract substantial foreign investment. But it does mean the currency is more exposed to changes in global appetite for UK assets and to the return investors require to provide that financing.
GBP/USD and GBP/EUR do not tell the same story
GBP/USD is heavily influenced by the US side of the pair: Federal Reserve expectations, US growth, Treasury yields and global risk sentiment. GBP/EUR is more directly about the relative UK/euro-area cycle and the Bank of England versus European Central Bank path.
For a broad view of sterling rather than one bilateral pair, the Bank of England publishes a trade-weighted sterling effective exchange rate index. Its 2026 weights give the euro area roughly 40% of the narrow index and the United States about 22%, illustrating why both European and US developments matter to the pound.
What would make the sterling outlook materially stronger?
A constructive combination would be UK inflation converging toward target without a sharp growth slowdown, real activity proving resilient, and the Bank retaining a relatively firm rate path without markets interpreting that firmness as a response to fiscal or inflation stress. Improving external balances or stronger demand for UK assets would add support.
What would weaken it?
The opposite combination would be more difficult: weaker growth, faster expected UK rate cuts than abroad, a deterioration in fiscal confidence, or an external shock that raises import costs while compressing real incomes. A persistent energy-price shock is particularly awkward because it can raise UK inflation and weaken real growth at the same time.
What to watch next
The immediate UK calendar is unusually concentrated: August CPI is due on 16 September 2026 and the next MPC decision on 17 September. The next quarterly balance-of-payments release is due on 30 September, followed by the Budget and OBR forecast on 28 October.
Those releases are more useful than a static year-end target. A sterling view should update when the relative rate, growth or fiscal story changes, not because the calendar moved forward by a month.
Primary sources
- Bank of England: Bank Rate and latest monetary-policy decision.
- Bank of England: Market Participants Survey, July 2026.
- Bank of England: sterling effective exchange rate index weights.
- Office for National Statistics: UK balance of payments.
- Office for National Statistics: consumer price inflation.
Checked 11 September 2026. Current Bank Rate: 3.75%. Latest CPI release: July 2026. Next CPI release: 16 September 2026. Next MPC decision: 17 September 2026. Next quarterly balance-of-payments release: 30 September 2026.