The trade gap including both goods and services came to $3.6 billion in May, up from $3.1 billion in April, the data office said.
Among traded goods, Britain ran a deficit of $12.6 billion in the month, which was partly offset by a $9 billion surplus in services.
Both imports and exports of goods rose in the month, in contrast with services, where exports declined slightly, led by a decline in exports of travel services, the ONS said.
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