If I have several dependent children in one sponsorship, does one child's inadmissibility affect the others?

Not necessarily, but it can in some circumstances. IRCC generally assesses each family member included in a sponsorship, including each dependent child, individually for admissibility. Inadmissibility under IRPA can arise from several different grounds — including health, criminality, security, or misrepresentation, among others — and each ground has its own test and its own consequences.

Whether one child's inadmissibility affects the rest of the family's application depends heavily on which ground is involved and how serious it is. In some cases, a family can still proceed with the application while the inadmissible child is excluded from it, addressing that child's situation separately. In other cases, particularly with more serious grounds, the issue can have broader implications for the application as a whole, including for family members who are not personally inadmissible.

Because this varies so much by the specific ground and the individual facts, there's no single rule that applies to every situation, and it's not something to assume will resolve itself in the family's favour. If one of your dependent children has been flagged as potentially inadmissible, it's important to get individual legal advice quickly to understand what it means for that child specifically and for the sponsorship application as a whole.