Section 15.1(3) of the Divorce Act empowers a court to grant an interim order for child support. Interim and permanent orders fall subject to the same criteria under the Divorce Act and the Federal Child Support Guidelines. An interim order continues in force until a permanent order is granted and is not automatically terminated by divorce.468Although section 17 of the Divorce Act relates only to applications to vary permanent orders and section 15.1 of the Divorce Act includes no express provision for the variation of interim orders, a court has an inherent jurisdiction to vary an interim order.469In the words of Voith J, of the British Columbia Supreme Court:
A compelling change of circumstances justifying variation of an interim order is a change that arises subsequent to the making of an order such that
one or both parties would be seriously prejudiced by waiting until trial or a final order (Hama v. Werbes,  B.C.J. No. 2558 at para. 10, 2 R.F.L. (5th) 203 (S.C.)). The court may consider a number of factual matters in deciding whether to vary an interim support order, including the completeness of the information on the application, the proximity of the trial date, whether the trial has been adjourned, the length of time since separation, the provision of correct, better or additional financial information, and a change in the means or needs of the payor and payee spouse respectively (Kirk v. Kirk et al., 2007 BCSC 67 at para. 60).
In ordering permanent child support, a trial judge is not bound by a preexisting order for interim child support.470An amount payable under an interim order may be adjusted retroactively by a trial judge, if an erroneous assumption was made concerning the obligor’s income.471However, a trial judge is not compelled to top up a pre-existing interim support order by a lump sum or supplementary periodic payments in light of a subsequent attribution of income.472Appellate courts have endorsed a general policy of not disturbing interim orders, unless there is a manifest error that requires immediate correction.473Interim variation orders, even though permissible under sections 15.1, 15.2, 16, and 17 of the Divorce Act, are not available as a matter of course. They should be regarded as exceptional. Courts generally frown upon multiplying interim proceedings and seek to encourage the parties to move without delay to a final resolution. If any inequities ensue, they can be addressed at trial.474
Section 11 of the Federal Child Support Guidelines empowers a court to order payments under a child support order to be made by way of periodic sums, a lump sum, or a combination of both. Given that the provincial and territorial tables under the Guidelines fix a monthly sum for child support based on the obligor’s annual income and the number of children, there appear to be significant limitations of the right of a court to order lump sum child support,
although no corresponding limitations apply to orders for spousal support.475
In the rare case where a lump sum order for basic child support is granted, the court should capitalize the periodic payments that would otherwise have been ordered.476Such capitalization may warrant actuarial evidence being adduced.477Capitalization of child support payments...