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Legalizing cannabis is a complicated business with lots of moving parts.

The question of how a credit card marijuana purchase will appear on your statement would seem not to make a list of the top 50 issues.

And it wouldn’t, except for two awkward facts:

U.S. law allows border officials to ban Canadians for life from their country for using marijuana in this country, even when it’s legal here. (A senior official confirmed last week that they are willing to do this in practice.)

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And credit card data can be stored in the United States, where it’s an open book to U.S. authorities, who don’t need a warrant to access it if it belongs to non-Americans. (The privacy agreements of all five of the big banks warn that customers’ financial data can be stored outside Canada, and be subject to the laws of the country it’s stored in.)

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So if the U.S. wanted to start assembling a list of at least a fair number of Canadian marijuana users after legalization, they certainly have a way of doing so.

Armed with credit card data that clearly showed a cannabis purchase, a U.S. border guard could quickly put a Canadian in an impossible position — admit to marijuana use and be banned for that, or deny it and be banned for lying.

For some time after legalization, it may be difficult to avoid using a credit card to buy marijuana legally, since only online channels will be open.

British Columbia, for example, will have only one bricks-and-mortar store ready to go on Oct. 17, and Ontario will have none at all until April 2019.

Some provinces have developed workarounds. One of the simplest is not making it obvious who the vendor is in credit card data.

Nova Scotia, where cannabis will be sold directly in liquor stores, solved the problem elegantly by entering purchases as NSLC (Nova Scotia Liquor Commission), which will make cannabis buying effectively invisible in the data.

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New Brunswick, where the provincial cannabis monopoly is separate from the provincial alcohol monopoly, hasn’t made a final decision.

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“We’re still trying to figure out the best option, but I can tell you that it’s not going to be Cannabis NB,” said spokesperson Mark Barbour. Tweet This

In Quebec, cannabis purchases will be entered by the individual Société québécoise du cannabis store. Spokesperson Linda Bouchard emailed an example entry: SQDC77003 DRUMMONDVILLE QC

That would seem to make it clearly identifiable.

“Measures were planned in our agreements with our financial institution to protect personal information, according to Canadian laws,” Bouchard wrote.

The Ontario Cannabis Store’s online portal will be the only legal way to buy cannabis in that province for more than five months. How will purchases be identified?

“We will have something to announce on payment and delivery soon,” spokesperson Daffyd Roderick wrote in an e-mail.

In Alberta, online cannabis purchases from the Alberta Gaming and Liquor Commission will be recorded simply as ‘AGLC,’ spokesperson Heather Holmen wrote in an e-mail.

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British Columbia has decided on how credit card purchases will be displayed, but won’t say what it is.

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“We’re doing what we can to mitigate the issue with the border, and being considerate of the sensitivities related to this issue,” said Liquor Distribution Branch spokesperson Kate Bilney.

“Obviously, if we say, ‘This is how B.C. cannabis purchases will appear on a transaction,’ and if (U.S. officials) see that in the media, then they will know. The expectation is that they won’t be purchasing cannabis from our stores, so therefore they won’t be privy to how that will be displayed.” Tweet This

Many provinces will allow for cannabis sales from private-sector retailers, where credit card purchases raise similar issues. They’re harder to fudge than sales by government agencies (with the interesting exception of Loblaw, which will operate 10 stores in Newfoundland.)

Canopy Growth will open retail stores in Manitoba, Saskatchewan and Newfoundland in October, and hopes to open stores in Alberta and Ontario.

“(Statements) will say the store that it was purchased from, the location, and the price. In no way does it say what was purchased, and that’s consistent with our online medical sales right now,” says spokesperson Catlin O’Hara.

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Nothing in federal law forbids cannabis retailers from selling things other than cannabis — T-shirts or hats, for example. However, some provinces will, and that means (in those provinces) that someone with a credit card purchase at a cannabis store was absolutely, definitely buying marijuana.

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Canopy’s mammoth growing facility in Smiths Falls, Ont. runs a gift shop as part of its visitor centre, O’Hara says.

“We currently sell merchandise — hundreds of different T-shirts, pillows, blankets, you name it, as well as pipes, bongs and things like that.”

If you’re able to buy cannabis in person, a debit card is a far better option than a credit card from a privacy point of view, since debit card data is processed and stored in Canada. (Cash, obviously, is still better than that.)

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