Under Section 9 of the Federal Child Support Guidelines (FCSG), the answer is no, the set-off is not automatic. Contino v. Leonelli-Contino, 2005 SCC 63 is the most important case with respect to this issue.
2. Section 9 of the FCSG reads as follows:
9. Where a spouse exercises a right of access to, or has physical custody of, a child for not less than 40 per cent of the time over the course of a year, the amount of the child support order must be determined by taking into account
(a) the amounts set out in the applicable tables for each of the spouses;
(b) the increased costs of shared custody arrangements; and
(c) the conditions, means, needs and other circumstances of each spouse and of any child for whom support is sought.
3. Barnard v. Barnard, 2016 BCSC 1710, recently gave a good summary of Contino and enumerated the most important principles:
 Section 9 does not automatically result in deviating from the Guidelines when assessing what amounts should be payable for child support.
 The factors listed in s. 9 should be weighed differently according to the specific facts of each case: Contino at para. 39.
 The set-off amount is a useful starting point but it has no presumptive value; a court will depart from it or make adjustments to it if it is inappropriate in light of the factors considered under ss. 9(b) and (c): Contino at para. 41. The set-off amount must therefore be followed by an examination of the continuing ability of the recipient parent to meet the needs of the child: Contino at paras. 41, 49. The court retains the discretion to modify the set-off amount where, considering the financial realities of the parties, it would lead to a significant variation in the standard of living experienced by the child as between the two households, “something which Parliament did not intend”: Contino at para. 51.
 Section 9(b) reflects that shared custody may increase the combined costs of raising children because there is often duplication of costs: Contino at para. 52.
 Under s. 9(c) the court is given “a broad discretion for conducting an analysis of the resources and needs of both the parents and the children”: and the objectives of the Guidelines require “a fair standard of support for the child and fair contributions from both parents”: Contino at para. 68.
 The court will be especially concerned with the standard of living of the child in each household and the ability of each parent to absorb the costs required to maintain appropriate standards of living in the circumstances: Contino at para. 68. Financial statements or budgets are necessary for this purpose.
4. Kennedy v. Kennedy, 2006 BCSC 190, where one party was earning approximately $32,580, and the other $23,900, the payor was ordered to pay $400 per month in a situation where the guideline amount was $580 and the off-set was $359, at paragraph 47.
5. Even if income is imputed, it is submitted that the full set off is inappropriate. In Mann v. Mann, 2007 BCSC 980, the Plaintiff’s earnings were $28,989, and the Defendant’s was $111,688. No off-set was ordered, at paragraph 77 for the one child under consideration. While this decision was appealed, only property and spousal support were changed.
6. A.L.M. v. N.J.O., 2015 BCSC 70, also noted the Contino factors, beginning with the set-off amount. It is trite to say that the set-off is not the end point of the consideration, and has no presumptive value, as indicated at paragraph 17 of T.J.B. v. B.A.F., 2014 BCPC 290.
7. A.L.M. goes on to the other factors after the set-off amount. At paragraphs 102 and 103, the court observes:
b) The increased costs of shared custody arrangements
 Section 9(b) recognizes that the total cost of raising children in “shared custody” situations may be greater than in situations where one parent has more than 60% of the parenting time. The court is generally called upon to examine the budgets and actual expenditures of both parents in addressing the needs of the children and to determine whether shared parenting has, in effect, resulted in higher costs globally. Increased costs would, in many circumstances, result from duplication because the child is effectively being given two homes. This then leads to an inquiry to determine what, if any, additional costs have been incurred by the payor as a result of the parenting arrangement.
 In this case, very little evidence was led to establish what, if any, additional costs the respondent has incurred as a result of meeting the threshold of 40%. The evidence establishes he has been in a new relationship for approximately one year. His new partner resides in a two-bedroom condominium. He pays his new partner $1,100 per month to contribute to the ongoing living expenses. How this amount is utilized was not explored in the evidence and, accordingly, I assume it is a contribution to the cost of maintaining the condominium, food and other living expenses. There is no evidence the respondent has incurred expenses or higher costs as a result of the shared parenting arrangement.
 In Contino at para. 54, the Court explained that in the absence of evidence to the contrary, it is possible to presume that the recipient parent’s fixed costs have remained unchanged and that her variable costs have been reduced only modestly by the increased parenting time of the payor. I find that this is true for the claimant.
c) The ability of each parent to bear the increased costs of shared parenting
 As stated, there is no evidence of any such increased cost. Both parties have found new partners. There is no evidence of the conditions, means, needs or other circumstances of each household…
8. After noting that it found the Claimant was financially responsible in her spending patterns, and that imposing financial liability on the Claimant for shared parenting would be onerous, the court found at paragraph 109 that it was not appropriate to use the set off and ordered basic table.
9. As noted in T.L.C. v. T.H.R., 2014 BCSC 1535, the court declined to depart from the table amount at paragraphs 19 and 20:
 I have no evidence of the claimant’s income between 2005 and 2011, and little evidence of the respondent’s income over that same period of time. Both parties have apparently re-partnered, but I have no information about the circumstances of either of the new partners. Further, neither party provided evidence of the costs that they faced in providing care for T.L.R. Finally, neither provided any evidence of note as to their conditions, means, needs and other circumstances, or those of T.L.R.
 Given this lack of relevant evidence, I am unable to grant the relief sought by the respondent. However, rather than dismissing his application, I will adjourn it generally in case he wishes to renew the application based on appropriate supporting material. Should he choose to do so, the claimant will, of course, have the opportunity to file responsive material of her own.
If you have concerns about child support, talk to a family law lawyer.