Britain spent a huge amount of money fighting the Revolutionary War, increasing national debt hugely and creating a yearly interest of nearly ten million pounds. Taxes had to be raised as a result. The trade which Britain relied on for wealth was severely interrupted, with imports and exports experiencing large drops and the recession which followed caused stock and land prices to plummet. Trade was also affected by naval attacks from Britain’s enemies, and thousands of merchant ships were captured.
On the other hand, wartime industry such as the naval suppliers or the elements of the textile industry which made uniforms experienced a boost, and unemployment fell as Britain struggled to find enough men for the army, a situation which would cause them to hire German soldiers. British ‘privateers’ experienced as much success preying on enemy merchant ships as almost any of their opponents.
The effects on trade were also short term, as British trade with the new USA rose to the same levels as trade with them in colonial form by 1785, and by 1792 trade between Britain and Europe had doubled. Additionally, while Britain gained an even larger national debt, they were in a position to live with it and there were no financially motivated rebellions like those of France.
Indeed, Britain was able to support several armies during the Napoleonic wars (and even field its own instead of just paying for other peoples). It's been said that Britain was even right to lose the war because of the economic benefits.
