For most applicants from countries where the legal systems are not based on common law, the common-law relationships are as much mysterious and difficult to understand for some, and convenient and beneficial for the other. For some, they face losing their permanent residency status for not declaring it in certain cases. For the other, it becomes a convenient way to get permanent residency status without even getting married. The minimum time threshold for a common-law relationship under IRPA is only one year. Note that in Canada, the thresholds vary in different jurisdiction. For example, in BC’s family law, the cohabitation period is at least for two years.
For people who do not declare it. There are two common reasons. One, they do not understand what it is. But the fact that you are from a different jurisdiction where there is no such thing is not an excuse before a Canadian immigration officer. Two, they vaguely understand what it is, but they are not sure if declaring it will have a negative impact on their cases, especially after they submit their applications. For example, you are not sure if adding a new family member will change your qualification in certain categories, such as those under the Express Entry; for another, your partner may not pass the medical examination, and you are not sure if this is a game changer in your application. The simple answer from IRCC is that you need to notify them immediately for any change of family composition, such as marriage and divorce.
In a worst scenario, you may face even removal from Canada. If you applied for permanent residency and the application is considered positively, you should receive a permanent resident visa (this is on your passport), and a legal document called Confirmation of Permanent Residence (CoPR). You need to come to Canada with this legal document to sign it before a CBSA officer to officially become a permanent resident of Canada (a process referred as “landing”). If your marital status on that legal document is “single”, but the CBSA officer deems otherwise, your permanent residence visa and CoPR may become invalid for having inaccurate information. As per IRPA, section 20 (1), you come to Canada without having a proper document:
20 (1) Every foreign national, other than a foreign national referred to in section 19, who seeks to enter or remain in Canada must establish,
(a) to become a permanent resident, that they hold the visa or other document required under the regulations and have come to Canada in order to establish permanent residence; …
This could trigger IRPR, section 228 (1) (c) (iii), and receive an exclusion order, and not allowed to enter Canada for another year.
(c) if the foreign national is inadmissible under section 41 of the Act on grounds of
(iii) failing to establish that they hold the visa or other document as required under section 20 of the Act, an exclusion order,
If you are not caught by the CBSA officer at the port of entry (airport, for instance), but caught by another IRCC or CBSA officer in a later date, you still face the potential ground for providing misleading or inaccurate information in your application (called “misrepresentation” in IRPA), and be deprived of your permanent residency status, and be banned to enter Canada for another five years, pursuant to IRPA section 40:
40 (1) A permanent resident or a foreign national is inadmissible for misrepresentation
(a) for directly or indirectly misrepresenting or withholding material facts relating to a relevant matter that induces or could induce an error in the administration of this Act;
(2) The following provisions govern subsection (1):
(a) the permanent resident or the foreign national continues to be inadmissible for misrepresentation for a period of five years following, in the case of a determination outside Canada, a final determination of inadmissibility under subsection (1) …
You can avoid all these by understanding the nature of a common-law relationship and notify the Canadian government, but if you do get into trouble with regard to this issue, consult professionals before you make any wrong decisions.
很多中国人在面对common-law关系如何上报给移民局时都比较犹豫。我猜想大部分人的犹豫来源于两方面：1. 我不知道这个common-law relationship到底是个什么东西。2. 我要是加了一个家庭成员，会不会影响我自己的移民申请，尤其是这个申请如果已经交掉了，之后我才发生变更，该不该告诉移民局?
家庭成员变更之前，最好咨询专业的移民法务人员，以免造成难以弥补的后果。你的CoPR上写明了你的婚姻状况。登陆时，假如你承认了你的婚姻状况跟CoPR上的不一致，会导致你的PR Visa失效。根据移民法IRPA第20条第1款a项：
20 (1) Every foreign national, other than a foreign national referred to in section 19, who seeks to enter or remain in Canada must establish,
(b) to become a permanent resident, that they hold the visa or other document required under the regulations and have come to Canada in order to establish permanent residence; …
稍微解释一下就是，登陆时必须带相应的有效文件。如果带的文件不是有效文件，CBSA可以根据IRPR第228条第1款c项iii，将申请人递解出境（exclusion order），比并处一年不得入境:
(c) if the foreign national is inadmissible under section 41 of the Act on grounds of
(iii) failing to establish that they hold the visa or other document as required under section 20 of the Act, an exclusion order,
那假如你不release给CBSA关于你的婚姻状况变更的信息，日后被发现了，又有misrepresentation (即提供虚假信息/虚假材料)的风险。 根据移民法第40条第2款a项，misrepresentation会面临取消移民身份并处5年不得入境:
40 (1) A permanent resident or a foreign national is inadmissible for misrepresentation
(a) for directly or indirectly misrepresenting or withholding material facts relating to a relevant matter that induces or could induce an error in the administration of this Act;
(2) The following provisions govern subsection (1):
(a) the permanent resident or the foreign national continues to be inadmissible for misrepresentation for a period of five years following, in the case of a determination outside Canada, a final determination of inadmissibility under subsection (1) …
因此，说和不说都有一定风险，正确的方式是提前咨询专业的移民法务人士。其他家庭陈成员变更比如生孩子，离婚了，跟同居伴侣分手了，都在此列。