1. In applications for condonation, courts must exercise discretion to achieve fairness in the interests of justice, considering factors including degree of non-compliance, explanation for delay, prospects of success, and avoidance of unnecessary delay. 2. A party who elects domicilium citandi et executandi in a contract is bound by that choice, and service at the chosen address is valid even if the process is not actually received, unless the party has properly notified the other party in writing of a change of address as required by the agreement. 3. Service effected on a responsible person in the employ of a party at the domicilium constitutes valid service under Rule 42 B (1)(b). 4. Condonation may be granted even where there is a finding of wilful default with no reasonable explanation, if the applicant demonstrates strong prospects of success on the merits and the interests of justice favor allowing the matter to be determined on the merits rather than by default.