Most vehicles have a manufacturer’s maximum recommended towing weight. It's usually listed in the handbook or vehicle specification sheet. You can also find it on the vehicle identification number (VIN) plate on the car. If in any doubt, contact your vehicle manufacturer.
When towing a trailer, the following needs to be considered:
The actual weight of the trailer and its load must not exceed the maximum towing weight permitted by the vehicle. For example, if the maximum towing weight of your vehicle is 2000kg and the trailer you are towing has an unladen weight of 500kg, then you can load up to 1500kg on your trailer providing the maximum gross weight of the trailer is 2000kg or above.