AVS and CVV Checks on Shopify in Canada: Postal Code Rules

A Calgary store selling gaming laptops gets an order for C$1,899.00 from a first-time buyer. The card passes, the billing postal code does not match, and the shipping address is a different city. The owner has ten minutes before the courier pickup. Ship it and risk a fraud chargeback on a C$1,899.00 order. Hold it and risk insulting a real customer who typed a postal code with a typo. AVS and CVV checks exist to make that call less of a coin flip, and in Canada they come with quirks that catch honest buyers and let careless merchants misread the result.

Quick answer: AVS and CVV checks compare what a buyer typed at checkout with what the card issuer has on file. AVS looks at the billing address digits and postal code. CVV looks at the security code on the card. A failed check is a risk signal, not a verdict. Shopify's own guidance is to ship physical goods only on orders that clear the address check when they go to Canada, the US or the UK, and to write to the buyer first when the check fails.

This guide is for you if:

• You sell on Shopify Payments in Canada and see orders with address or security code mismatches.
• You have lost a fraud dispute on an order that failed AVS and you shipped it anyway.
• You want clear rules for when to hold, when to ship and when to ask the customer.

Last updated: 23 October 2026

Disclosure: ChargeFix publishes this guide and sells an app that helps with Shopify Payments disputes. The Shopify guidance comes from Shopify's Help Center, listed at the end. Shopify's page on prevention is short on detail about codes and labels, so this guide describes how the checks work in general and tells you to match the wording you see in your own admin.

TL;DR

• AVS compares the numbers in the billing address and the postal code. CVV compares the card's security code.
• Shopify says to consider holding back any order that fails the address check, and to write to the customer first.
• Canadian postal codes cause false failures: spaces, the letters O and I mistyped as 0 and 1, and unit numbers.
• A mismatch is a reason to ask a question, not a reason to cancel, and AVS checks work best alongside other signals.
• Save the order's address and risk details. They support a fraud dispute.

Do this today

1. Pull your last 20 orders that showed an address or security code mismatch.
2. Note which ones you shipped and which became disputes.
3. Write a one page rule for holding orders by value and mismatch type.
4. Draft a short "confirm your address" email.
5. Check that your checkout asks for the unit number in its own field.

AVS and CVV checks on Shopify in Canada: the process in one table

Step	What you do	Why
1. Spot the signal	Open the order and read the address and security code results	Risk starts at the order, not the dispute
2. Classify	Postal code only, street only, both, or security code	Different failures mean different things
3. Compare	Billing vs shipping, first order vs repeat	Context decides the risk
4. Contact	Ask the customer to confirm	Shopify advises contacting the customer first
5. Decide	Ship, hold or cancel	Write the reason on the order
6. Save	Address, messages, risk details	They feed any later dispute
7. Review	Check disputes against checks monthly	Adjust your rules

What are AVS and CVV checks?

AVS stands for address verification service, and address verification is the name used by most card networks. When a buyer pays by card, the digits of the billing address they typed, usually the street number and the postal code, are compared with the address the card issuer has on file. CVV is the card verification value, the three or four digit security code, and the check is whether the number the buyer typed matches the card.

Check	What it compares	What a failure may mean
AVS, postal code	The code typed vs the issuer's record	Typo, old address, or a stolen card
AVS, street	The street number typed vs the issuer's record	Typo, moved house, or a stolen card
CVV	The security code typed vs the card	Typo, or someone who has the number but not the card
Both fail	Address and code together	Higher risk, still not proof

These are signals the issuer sends back. They do not tell you who is typing. A thief with a full set of stolen details can pass every check. An honest buyer with a freshly moved address can fail one.

What does Shopify say about AVS checks?

Shopify's page on preventing chargebacks gives two direct lines. For physical goods shipped to the United States, the United Kingdom or Canada, it suggests shipping only when the order clears AVS. And it says you can reach out to the customer before sending goods to an address that fails. The same page says to investigate suspicious orders before you fulfill them.

The page does not discuss CVV, and it does not explain the codes. So treat Shopify's guidance as a process, not a rulebook: look at the check, decide whether the order is suspicious, and ask before you ship if it is.

Shopify says	What it means in practice
Consider shipping only orders that pass AVS	Make passing a default condition for high value goods
Reach out to the customer before a failed address ships	Ask first, then decide
Investigate suspicious orders before fulfilling	Check the details before you pack the box

Shopify also says that, for fraud related disputes, receipts at payment help. That matters because an order confirmation sent at once is a record the customer received, and it links to the shipping address you used.

How do Canadian postal codes trip AVS checks?

A Canadian postal code has six characters in a letter, digit, letter pattern, a space, then digit, letter, digit, as in A1A 1A1. That pattern is easy to type wrong, and a surprising number of honest orders fail because of it.

Cause	Example	Result
Space missing or extra	T2N1N4 vs T2N 1N4	Usually fine, but some forms trip
Letter O typed as zero	K1A 0B1 typed as K1A OB1	Postal code mismatch
Letter I typed as one	A1A 1A1 typed as AIA 1A1	Postal code mismatch
Lowercase letters	t2n 1n4	Usually fine, but check
Old postal code	Customer moved, card not updated	Mismatch with issuer
Wrong province code	Card billed in Ontario, ships to BC	Billing is not the same as shipping

Canadian postal codes never use the letters D, F, I, O, Q or U, and no code starts with W or Z. So an "O" in a postal code is almost always a typed zero in the wrong place, or the other way round. That small fact helps you read a failed check: if the code contains one of those letters, the customer likely made a typo.

A failed address verification caused by a typo is a customer service problem. A failed AVS check caused by a stolen card is a fraud problem. The signal looks the same. Your job is to tell them apart with one question.

Why do unit numbers and rural addresses cause AVS failures?

AVS compares digits, so any address that is not a plain street number and name can go wrong.

Address style	Problem	Practical fix
Apartment or unit number	Customer puts it before the street number, or in the wrong field	Use a separate unit field at checkout
Rural route or box number	Digits are not a street number	Ask for the full line from the bank statement
PO box	Billing address is a box, shipping address is a street	Expect a mismatch and ask
Highway or concession number	Long numbers confuse matching	Confirm by email
Accented French street names	Characters stripped or changed	Ask the customer to retype without accents
Recent move	Issuer still holds the old address	Ask for the address on the statement

The suite or apartment number is the most common culprit. A customer in a Vancouver condo types 1204, 555 Granville St, then the match engine compares 1204 with the street digits 555. Keep a clear unit number field at checkout (address verification works best when it is filled in) and tell customers to use the address that appears on their card statement. Fewer failed AVS checks follow.

What does a failed AVS check actually mean?

Address verification gives you three kinds of answer, and each one calls for a different reaction.

Think of AVS results as three groups: a full match, a partial match and no match. Your admin may use its own wording, so read what Shopify shows on the order and map it to these groups.

Result	Reading	Suggested move
Postal code and street match	Low risk from this signal	Ship if the rest looks normal
Only postal code matches	Moderate; street may be a typo or unit issue	Check the unit number, then ship or ask
Only street matches	Moderate; postal code may be a typo	Check the letters and digits
Neither matches	Higher risk	Contact the customer before shipping
Check not available	Unknown	Treat as unverified and use other signals

A partial address verification result is not a verdict. A customer who moved last month will fail the street. A customer who typed the wrong postal code will fail the postal code. What matters is the combination: a new customer, a high order value, a rush shipping request and a failed check together should stop you.

How do you use AVS and CVV checks with other signals?

No single check decides a fraud case. Combine AVS checks with other signals and weight them by order value.

Signal	Lower risk	Higher risk
AVS result	Full match	No match
CVV result	Match	Mismatch
Billing vs shipping	Same address	Different city or province
Customer history	Repeat buyer, prior undisputed orders	First order
Order value	Typical for your store	Unusually high
Shipping speed	Standard	Rush, overnight
Email and IP	Consistent with the address	Free throwaway email, far-off location

The point of AVS checks is to build a short checklist you apply the same way every time. A rule you wrote down at 9 a.m. beats a hunch at 4:45 p.m. with a courier at the door.

Order review rule (example, adapt to your store)

Under C$150.00 .......... ship unless AVS and CVV both fail
C$150.00 to C$500.00 .... ship if AVS matches; ask if AVS fails
Over C$500.00 ........... ask on any mismatch, or if first order with rush shipping
Over C$1,500.00 ......... call or email on any mismatch; ship only after a reply

Always hold: AVS fails AND billing differs from shipping AND first order

Adjust the thresholds to your own margins. A store selling C$25.00 candles can accept more risk than a store selling C$1,899.00 laptops.

How do you contact the customer about an AVS mismatch?

Shopify's guidance says you can reach the customer before anything ships to a failed address. Do it fast, make it friendly and never accuse.

Message to a customer after an address mismatch

Subject: Quick check on your order #[number]

Hi [first name],

Thanks for your order. Before we ship, I want to make sure it reaches
you. Could you confirm the billing address on your card statement,
including any unit number and the postal code? We ask because the bank
could not match the address you entered, which happens with typos and
recent moves.

Reply by [date] and we will ship the same day. Your statement shows this
charge as [statement name], and my number is [phone number].

[Name], [store]

Do not put your suspicions in the message. Do ask for the exact address. A genuine customer replies within hours. A fraudster often does not reply, or sends details that still do not match.

If the customer replies with a corrected postal code, save the email. It shows you checked, and it becomes part of the order record if a dispute follows.

What do AVS and CVV checks do for a fraud chargeback?

A failed check is a risk signal at the time of order. A passed check is evidence of care when a dispute arrives. For a fraudulent dispute, Shopify's evidence includes billing information, the IP address and country, shipping and tracking, and fulfillment details. Shopify Payments fills in some of this automatically, such as billing and shipping addresses and shipping information.

Evidence	Where it comes from	Role in a fraud dispute
Billing and shipping addresses	Order, filled in by Shopify Payments	Shows where the goods went
AVS result and notes	Your order record	Shows you checked
Messages confirming the address	Your inbox, saved as PDF	Acknowledgment from the cardholder side
IP address and country	Order details	Consistency with the address
Fulfillment and tracking	Shopify and the carrier	Delivery to the address on the order
Prior undisputed orders	Order history	History with the same details

A passing check does not win a case on its own. A card company can still decide that the cardholder did not authorize the sale. But an order that passed the checks, shipped to the confirmed address and has a delivery record is stronger than one with a blank file.

Fraud disputes also come with a limit. Shopify cannot request early resolution for Visa disputes with a Fraudulent reason code or for American Express disputes. So prevention counts for more on these.

Is it worth holding an order? A worked example in C$

Take the Calgary laptop order. The value is C$1,899.00.

Case A: ship without checking, order is fraud

Order amount         = A = C$1,899.00
Fee                  = F = C$15.00 (returned only on a win)
Goods lost           = C$1,500.00 cost price (illustrative)
Chance of winning    = c = 0.15 (illustrative: shipped to a failed address)

Concede:  A + F = C$1,914.00 and the goods are gone
Fight:    0.85 x 1,914 + 30 = C$1,657.00 expected loss

Now the same order with a hold and a message.

Case B: hold, ask, the customer is genuine

Held for 1 business day
Chance the customer waits       = 0.90 (illustrative)
Revenue kept                    = 0.90 x C$1,899.00 = C$1,709.10
Revenue lost to the hold        = C$189.90
Chargeback risk avoided         = a C$1,914.00 loss if it was fraud

If 1 in 20 failed orders is fraud (illustrative):
Expected fraud loss avoided     = 0.05 x C$1,914.00 = C$95.70 per held order
Expected lost sales             = 0.10 x C$1,899.00 x 0.95 = C$180.41 per held order

On these made up numbers, holding every failed order loses money. The lesson: hold selectively. High value, first order and a total mismatch together justify the hold. A C$40.00 order with an apartment typo does not. Win rates and fraud shares here are illustrative, not Canadian statistics. We found no Canadian figure for how often failed AVS orders are fraud, so use your own order history.

How do you answer a fraud dispute on an order that failed AVS?

If you shipped anyway after confirming the address with the customer, say so. If you shipped without asking, be honest: show what you do have.

Draft reply to a fraudulent chargeback where AVS was partial

Order #[number], placed [date] for C$[amount].

Summary
The cardholder disputes the charge as unauthorized. The order passed the
card security code check. The postal code on the card did not match at
checkout, so we emailed the customer on [date] and the customer replied
on [date] confirming the address. The goods shipped on [date] and
Canada Post delivered on [date] to the confirmed address.

1. Customer confirmation
   Email thread saved as PDF (file 1).

2. Order and address
   Order details with billing and shipping addresses (file 2).

3. Delivery record
   Tracking PDF showing delivery to the address on the order (file 3).

4. History
   Previous undisputed orders on the same account, if any (file 4).

Write only what the files show. If the customer never replied, do not claim they confirmed. State that you asked and shipped anyway on your own judgment, or leave that point out.

Which cases are worth fighting after an AVS or CVV failure?

Case	Likely strength	Move
Passed AVS and CVV, delivered, prior orders	Strong	Fight, lead with delivery and history
Failed AVS, customer confirmed address by email, delivered	Reasonable	Fight, lead with the confirmation
Failed AVS, no contact, delivered	Weak	Fight only if other signals line up
Failed AVS and CVV, shipped to a new address, no contact	Weak	Concede and learn
Refunded before the chargeback began	Not a fight	Show the refund record

Strong cases combine passed checks and a delivery record. Weak cases ship against the warning and have nothing else to show.

What should your checkout do to cut false AVS failures?

Small changes at checkout cause fewer failures and fewer unneeded holds.

1. A separate unit number field. Prompt customers to use it.
2. A hint text. "Enter the billing address exactly as it appears on your card statement."
3. Postal code formatting. Accept the code with or without a space, in any case.
4. A province field. Keep it in line with the postal code.
5. A phone number. It helps you reach the customer quickly.
6. A gift option. Billing and shipping will differ for a gift, and a note tells you why.

Change	Effort	Effect
Separate apartment field	5 minutes	Fewer street mismatches
Hint text	5 minutes	Fewer stale billing addresses
Phone number required	2 minutes	Faster contact
Gift note field	10 minutes	Explains billing and shipping differences

Check what your theme and checkout settings allow. Not every store can change the form.

What should you record when AVS checks fail?

AVS checks only help a dispute if you wrote down what they showed and what you did about it. The order page is the live record, but statuses can change and staff forget. A two line note on the order takes under a minute.

Order note after failed AVS checks

Order #: ________   Date: ________
AVS result seen: ______________   CVV result seen: ______________
Billing vs shipping: [ ] same  [ ] different  (city/province: ________)
First order?  [ ] yes  [ ] no
Action: [ ] shipped  [ ] asked customer  [ ] held  [ ] cancelled
Customer reply saved as PDF?  [ ] yes  [ ] no   Date: ________
Decision made by: ____________

What you record	Why it helps later
The AVS and CVV results as you saw them	Proves you looked
The action you took	Shows a process, not luck
The customer's reply	Acknowledgment from the cardholder side
The date and time	Lets you match events to the shipping scan

Staff who run AVS checks in the same way every time make it easier to answer the dispute reviewer. A note that says "AVS partial, asked customer, replied same day, shipped" is worth more than a screenshot with no story. Review the notes once a month. If most of your failed AVS checks turn out to be typos, loosen the hold rule. If most turn into disputes, tighten it.

How do AVS checks interact with billing and shipping differences?

A billing address and a shipping address that differ are common and usually innocent: gifts, work addresses, parents buying for students. The signal is the combination of a failed AVS check, a different shipping address and a first order.

When the shipping address differs, check:

1. Does the shipping name match the billing name?
2. Is the shipping address a freight forwarder or a hotel?
3. Is it in a different province from the billing address?
4. Did the buyer choose rush shipping?
5. Is it the buyer's first order with you?

Two or more yes answers are enough to ask a question. For more on this signal, see our guide to billing and shipping address mismatches.

How does ChargeFix help with AVS and CVV checks?

ChargeFix works after a dispute opens, not at the order stage. It is built for Shopify Payments disputes.

1. Dispute fetched. ChargeFix fetches the chargeback when it opens.
2. Records read. It reads the order, the addresses, the fulfillment and tracking data and the refund history.
3. Evidence scored. It flags what is present and what is missing, such as no confirmation email on a failed address, and gives a plain verdict: worth fighting, improve the evidence first or weak evidence.
4. Letter from facts. The response is drafted only from verified facts, so it will not claim a confirmation that your records do not show.
5. Your choice of mode. ChargeFix prepares each response in Manual mode, which is the default. You review and file it, or let Auto mode handle them. Auto mode is on Starter plans and above, off until you turn it on and confirm.

ChargeFix handles Shopify Payments disputes only. It cannot promise a win, because the card company decides, and it does not screen orders before they ship. It stores minimal data: case ID, amount, reason, status, dates and shop settings. The free plan includes 2 filings a month, and every paid plan starts with a 14 day free trial.

What does a dated plan for a fraud dispute on a failed AVS order look like?

This plan assumes the shortest window, 7 days.

Day	What you do	Done when
Day 0	Dispute opens. Note amount, order and due date.	You know the deadline
Day 1	Pull the order, address and check results	Facts written down
Day 2	Find any customer confirmation email; save as PDF	Message saved
Day 3	Pull the tracking PDF	Delivery to the address confirmed
Day 4	Decide: fight or concede	Decision written down
Day 5	Draft the response, strongest proof first	Every claim points to a file
Day 6	Check file sizes and readability, then file	Confirmation shows in admin
Day 7	Spare day	Nothing left to do
Up to 75 days later	Decision arrives	Update your hold rules

If the cardholder realizes a family member made the purchase, ask them to request a withdrawal from their bank. The letter must be on bank letterhead and can take 30 to 90 days. Because Shopify cannot ask for early resolution on this type of Visa case, file your evidence without waiting.

What is different about AVS and CVV checks in Canada?

Topic	What applies in Canada	What to do
Fee	C$15 or US$15 by payout currency	Cost each case in your payout currency
Response window	7 to 21 days, no extensions	Plan for the shortest
Card company decision	Up to 75 days after you submit, and final	Do not expect a quick answer
Postal code format	Letter digit letter, space, digit letter digit	Accept either spacing
Letters not used	D, F, I, O, Q and U never appear	Spot typos quickly
Shopify Protect	US stores only, fraud and unrecognized reasons only	It does not cover Canadian stores
Complaints	Shopify Payments (Canada) acknowledges within 5 business days, decides in writing within 45 days	Raise a complaint with your processor first

Quebec. Quebec addresses often include accented characters and French street types, such as rue or boulevard. A customer may type their billing address one way and their bank holds it another. Ask them to copy the address from their statement. If you write to Quebec customers, send the confirmation message in a language they read.

Rural and PO box addresses. Rural routes, general delivery and PO boxes are valid in Canada but rarely match a street number. Expect a mismatch and ask.

Privacy. An address, an IP and an email are personal information. Keep what the dispute needs, and treat the record with the same care as the customer's order. The privacy rules that apply to your store depend on your province and size, so ask an adviser if you are unsure.

Consumer law. Consumer protection law differs by province. The sources we used set no Canadian rule on pausing an order over an address mismatch, so this guide states none.

Where to complain. Shopify Payments (Canada) acknowledges a complaint within 5 business days and gives a final written decision within 45 days. The Financial Consumer Agency of Canada supervises the Code of Conduct for the Credit and Debit Card Industry in Canada but does not decide individual disputes.

What are the 10 mistakes to avoid with AVS and CVV checks?

1. Treating a failure as a verdict. It is a signal, not proof.
2. Ignoring the check on a big order. Shopify says to consider shipping only passing orders.
3. Cancelling without asking. You lose honest buyers for no reason.
4. Missing postal code typos. The letters O and I are the usual suspects.
5. No apartment field. Condo buyers fail street matches.
6. Not saving the confirmation. An email that fixes the address is evidence.
7. Shipping to a forwarder without a question. Ask first.
8. Refunding after the chargeback began. Shopify does not allow it.
9. Attaching links. Links are not allowed. Save pages as PDF.
10. Missing the window. There are no extensions, and the fee is not refunded.

Frequently asked questions

What are AVS and CVV checks?

AVS compares the billing address digits and postal code a buyer typed with the address the card issuer holds. CVV compares the three or four digit code typed with the card. Both come back as results on the order. They are risk signals, not proof of who is paying.

Should I ship an order that fails AVS?

Shopify's guidance is to ship to Canada, the US or the UK only after the address clears AVS, and to message the buyer when it does not. For small orders, a typo is likely. For large first orders, ask before you pack.

Why do Canadian postal codes fail AVS checks?

The format is easy to mistype: letter, digit, letter, then digit, letter, digit. Customers type the letter O as zero or the letter I as one. Canadian codes never use D, F, I, O, Q or U, so those letters in a code point to a typo.

Does a passed AVS check win a chargeback?

No. It helps your record and shows you took care at the time of the order, but the card company can still rule that the cardholder did not authorize the sale. Combine the passed check with delivery proof, a confirmed address and any history of prior undisputed orders.

Can I refund a fraud dispute after it opens?

No. Shopify says you cannot refund once a chargeback has begun. You can refund while it is an inquiry. Shopify also cannot request early resolution for American Express disputes, or for Visa cases that carry the Fraudulent code, so a withdrawal letter will not speed those up.

What should I ask a customer after a mismatch?

Ask them to confirm the billing address on their card statement, including the apartment number and postal code. Keep it friendly, do not accuse, and give a clear time for a reply. Save the reply as a PDF, because it becomes evidence if a dispute follows.

Do unit numbers affect AVS checks?

Yes. AVS compares digits, so a unit number typed in the wrong place can scramble the street match. Put a separate field for it at checkout, and ask customers to copy the address from their card statement rather than from memory or an old delivery profile.

Is a failed CVV check the same as a failed AVS check?

No. CVV checks the code printed on the card, and AVS checks the address. A failed CVV can mean a mistyped code or someone who has the card number but not the card. Treat a failure in both as higher risk than either alone.

Are there Canadian rules on pausing an order after a failed check?

No source we read sets a Canadian rule on pausing an order after an address check fails, so we state none. Put your hold policy in writing and ask your provincial consumer office or a lawyer if you need certainty.

How does ChargeFix help with AVS and CVV checks?

ChargeFix works once a dispute opens. It reads the order, addresses, tracking and refund data, flags missing confirmations and drafts the letter from verified facts. In Manual mode, the default, you check each draft and file it yourself. It cannot promise a win.

Start free trial with ChargeFix

You now have a hold rule, a customer message and a response template for disputes that follow AVS and CVV checks. What most stores lack is the time to find the confirmation email, pull the address record and build the letter before the deadline. ChargeFix reads your Shopify order data, shows what is missing, writes the letter from verified facts and leaves the filing to you in Manual mode, with Auto mode there for the cases your own rules cover.

The free plan includes 2 filings every month, and every paid plan starts with a 14 day free trial. There is no cut of what you win, and no contract.

Ready to answer every dispute that follows AVS and CVV checks on Shopify in Canada with the records you already have? Start free trial

Sources

• Shopify Help Center, "Preventing chargebacks"
• Shopify Help Center, "Reasons for a chargeback or inquiry"
• Shopify Help Center, "Resolving a chargeback or inquiry"
• Shopify Help Center, "Protecting an order with Shopify Protect"
• Shopify Payments (Canada), "Code of Conduct complaint handling"
• ChargeFix, "chargefix.pro"
• Stripe, Best practices for preventing fraud: further reading on stopping disputes before they start
• Adyen, Manage disputes: further reading on how another payment provider handles disputes