Property investors have less than a fortnight to file their self-assessment tax returns.
Her Majesty's Revenue and Customs (HMRC) has issued a reminder to landlords, the self-employed and anyone with "complicated tax affairs" that they face a fine if they miss the deadline.
Last year, one in ten failed to send in their completed tax returns by January 31st.
HMRC said that this year, it had employed podcasts to help people struggling with the form.
"We've got a podcast out on our website that goes through the process of filling in a return, an introduction to Self Assessment online, and the usual Self Assessment helpline number," a spokesperson said.
Low interest rates have encouraged more and more people to buy property as an investment, which has added to the number needing to file self-assessment tax returns.
Any income that has not been taxed at source needs to be declared in this way.
Fixed fines and interest on anything owed will apply if the deadline is missed.
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