Pound sterling (GBP) exchange rate API

Sterling is one of the oldest currencies still in use and one of the most actively traded, with GBP/USD (“cable”) and EUR/GBP among the major pairs. UK companies, marketplaces and payroll tools typically need it in both directions – pricing UK products abroad and translating foreign revenue back into pounds. The fxapi GBP exchange rate API gives you those rates with base_currency=GBP, from live values to daily history back to 1999.

GBP facts for developers

• Where it’s used: the United Kingdom. Jersey, Guernsey and the Isle of Man issue their own pound notes at par (fxapi codes JEP, GGP, IMP), and the Falkland Islands pound (FKP), Gibraltar pound (GIP) and Saint Helena pound (SHP) are also fixed at par with sterling.
• Symbol and formatting: £ before the amount, comma thousands separator, period decimal: £1,234.56.
• Minor unit: 2 decimals (pence). Equity prices are often quoted in pence – divide by 100 before converting.
• Central bank: the Bank of England sets UK monetary policy.
• Regime: free float. The UK never joined the euro.
• Events in the historical data: after the EU referendum on 23 June 2016, sterling fell sharply on 24 June – the sample date on this page – to its lowest level against the dollar in about three decades. In late September 2022, after the government’s “mini-budget”, GBP/USD dropped to a record low.

Get GBP rates with the fxapi API

/v1/convert (Basic plan and up) returns converted amounts directly, with an optional date for back-dated invoices. This PHP snippet uses plain cURL to convert a £1,250 invoice into USD and EUR at the Brexit-vote rate:

<?php
$query = http_build_query([
    'base_currency' => 'GBP',
    'currencies'    => 'USD,EUR',
    'value'         => 1250,
    'date'          => '2016-06-24',
]);

$ch = curl_init("https://api.fxapi.com/v1/convert?$query");
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER     => ['apikey: ' . getenv('FXAPI_KEY')],
    CURLOPT_TIMEOUT        => 10,
]);
$body   = curl_exec($ch);
$status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if ($status !== 200) {
    throw new RuntimeException("fxapi returned HTTP $status");
}

foreach (json_decode($body, true)['data'] as $code => $item) {
    printf("£1,250.00 = %s %s\n", number_format($item['value'], 2), $code);
}

On the Free plan, fetch the rate with /v1/historical and multiply yourself. More in the PHP guide and the currency converter API overview.

Things to watch

• Pence vs pounds. Mixing GBX prices with GBP amounts produces errors of exactly 100× – validate units at the boundary.
• Event days. Daily values are end-of-day (UTC); on days like 24 June 2016 the intraday range was far wider. Use the fluctuation endpoint for period moves.
• VAT rounding. Round to pence per your invoicing rule, not per conversion step – see currency rounding and precision.

Popular GBP pairs

Request any of these pairs – or any other combination of the 190+ supported currencies – with base_currency=GBP:

Monthly averages and fluctuation for GBP

# Monthly average GBP rates for 2025 (IAS 21 / ASC 830)
curl -G "https://api.fxapi.com/v1/average" \
  -d date_from=2025-01-01 -d date_to=2025-12-31 -d period=month \
  -d base_currency=GBP -d currencies=USD,EUR,JPY \
  -H "apikey: $FXAPI_KEY"

# How did GBP move over the last year?
curl -G "https://api.fxapi.com/v1/fluctuation" \
  -d date_from=2025-10-01 -d date_to=2026-10-01 \
  -d base_currency=GBP -d currencies=USD,EUR,JPY \
  -H "apikey: $FXAPI_KEY"

See the historical exchange rates API, average rates API and documentation for every parameter.

GBP is one of 190+ currencies in fxapi, the foreign exchange rate API for developers – live rates, daily history since 1999 and monthly averages with one API key.

Frequently asked questions