You will have to lay down a security deposit while renting a self storage unit. Some facilities may take this charge on pretext of other payments such as caution fee, safety deposit, emergency fund, or by some other names. Some deposits are levied as a one-time fee, while other companies such as Store Friendly Singapore keep it as a deposit and will be refunded to their customers at the end of the contract. In case you are closing your storage unit subscription, you might be required to pay for any additional fees or penalties incurred during your storage space usage, and this will be directly deducted from the security deposit. If you have any outstanding rental dues, these may also be subtracted from the deposit amount and you will get the remaining amount.
In case you are dealing with a company that has a known history of tricking their customers by avoiding the release of the security deposit, do your best to get a receipt and in writing about the charges that are responsible for you not receiving the complete payment. If they seem adamant about issuing any such certificate, don’t hand over your key, but let them know that you are not willing to close the subscription yet, and get professional help from the authorities at the earliest.