Under Zambian law, the key difference lies in when an employer must give advance notice and the circumstances that justify each type of dismissal.
Summary dismissal is immediate dismissal without notice, but it is only permitted in specific circumstances [Employment Code Act, S.50]. An employer can summarily dismiss an employee for: gross misconduct inconsistent with the employment contract; wilful disobedience to a lawful order; lack of skill the employee was warranted to possess; habitual or substantial neglect of duties; continual absence without permission or reasonable excuse; or misconduct under the employer's disciplinary rules where summary dismissal is the specified punishment. When an employer summarily dismisses an employee, they must still pay all wages and accrued benefits due up to the date of dismissal [Employment Code Act, S.51].
Dismissal with notice, by contrast, is the standard form of dismissal for other reasons (such as redundancy or performance issues that do not amount to gross misconduct). This requires the employer to give advance notice as prescribed in the Employment Code Act [Employment Code Act, S.53]. The notice period allows the employee time to seek alternative employment and provides procedural fairness.
In summary, summary dismissal is only for serious breaches and takes immediate effect, while dismissal with notice applies to other terminations and requires advance warning to the employee.