A week after property owners were warned their assessments will be higher this year, some are worried an inflated assessment means they'll no longer qualify for B.C.'s Home Owner Grant.

Letters are arriving in tens of thousands of Metro Vancouver mailboxes this week informing owners their property assessments will spike. The letters being sent before the new year are to warn homeowners who will see the highest spikes, while the rest will get their notices in January.

Each year, the assessments are calculated based on data collected on July 1, and this year the real estate market was at an all-time high on that day.

But the market took a turn just a month later, when the government rolled out its foreign homebuyers tax which saw some sales fall through and some buyers pull out of the market altogether.

Last week, the BC Assessment Authority issued a warning to homeowners, saying that owners of single-family homes may see their 2017 assessment increase between 30 to 50 per cent from last year.

Those seeing the highest increases will be in Vancouver, Squamish, Burnaby, Tri-Cities, Richmond, Surrey and on the North Shore, the statement said.

Those in strata-run properties in the same regions will see increases between 15 and 30 per cent.

The sudden spike means some homeowners may no longer qualify for the province's Home Owner Grant, which reduces the amount of property tax the homeowner is expected to pay.

Taxes for homeowners whose property is valued at $1.2 million or less may be reduced $570 with the help of the grant. Those with a property of a higher value can still qualify as long as the assessment is under $1.314 million.

The new assessments may push homeowners over the eligibility threshold, and some say they're worried they'll have to move.

One property owner told CTV News their assessment went up by close to $500,000, and without the Home Owner Grant, they will have to move somewhere with lower taxes.

"I think it's not fair… My income didn't go higher," another homeowner said.

She hopes the government will increase its eligibility threshold so she can continue to afford the taxes on her home.

Jordan Bateman with the Canadian Taxpayers Federation said some homeowners may be spending hundreds, if not thousands, of dollars more in 2017.

It will take a political decision to change the threshold for the grant.

"Why not get ahead of the issue and let people have a good Christmas knowing if they're going to get relief or not?" he suggested.

The threshold was already increased to $1.2 million earlier this year, and so far the Liberals haven't said whether it will change again.

"The finance minister is always thinking about that with every budget he puts together," Premier Christy Clark said.

"We have raised it over the years several times, so that's a decision for another day."

With a report from CTV Vancouver's Maria Weisgarber