We're being urged to get check our 2019 ITIS rate, request tax refunds or update our addresses before the end of the year.
The Taxes Office is warning of disruption in January, as the department relocates to La Motte Street.
More than 120,000 paper files will be moved, and a new computer system introduced.
Comptroller of Taxes, Richard Summersgill told Channel 103 that anyone who puts off their query will face a wait:
"We're trying to get as many people who would normally come to us in January to come in December instead. If you do come in January, we'll be able to give you very general advice, take your details and put your query in a queue. We'll work through it once the new system is up and running."
Businesses with new employees starting in January are being asked to arrange for them to register for tax before the end of December.
You can find out more about the disruption on Gov.je.
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