Douglas Council says the amount of unpaid rates at the end of the financial year was more than twice the previous year's figure.
A report to the local authority's executive committee revealed 99.3 per cent of rates were paid on time last year, down 0.2 per cent.
In total, £348,033 was outstanding - well up on the previous year's £148,546.
The report from the council's director of finance also said there was £472,171 in outstanding sundry debts - up from £139,476 the year before.
Chief Minister faces questions over employment scheme
Road closures across Island for cycle race this weekend
Douglas Beach Day underway this morning
Large cruise ship visiting today
Southern show kicks off today
Government minister meets with new PM Andy Burnham
150 Ukrainians aided as government schemes come to end
No ministerial discussions about magazine article on egaming crime