GST/HST Change-In-Use Self-Assessment Calculator

Moving a property from commercial to personal use isn't a paperwork-free decision. The Excise Tax Act treats it as a deemed sale at fair market value, GST/HST included.

Reading This Tool

How To Use This Calculator

Enter the property's fair market value at the time of the change, and the commercial use percentage before and after.

A decrease in commercial use triggers self-assessed GST/HST on the fair market value of the portion converting away from commercial use, effectively treating that portion as sold to yourself at that moment.

Your Inputs

FMV Of The Property At The Time Of Change $500,000

Commercial Use Percentage Before The Change 100%

Commercial Use Percentage After The Change 40%

Applicable GST/HST Rate 13.0%

An increase in commercial use works the other direction, generally allowing an input tax credit rather than triggering self-assessment. Certain thresholds and de minimis rules can affect whether a small change actually needs to be reported.

Self-Assessment Result

GST/HST To Self-Assess

Decrease In Commercial Use

0 pts

FMV Of The Converting Portion

Commercial Use Before vs. After

This models the core self-supply mechanic on a decrease in commercial use only. Specific elections and thresholds, including special treatment for personal residences with a minor commercial component, can change or eliminate this outcome, get this confirmed before relying on it.

Changing how a property is used and want it reviewed first?

Talk To Our Corporate Tax Team →