The company registration number can be found on the Integrated Companies Registry Information System (ICRIS).
The details for most registered businesses can be found on the Suruhanjaya Syarikat Malaysia (SSM).
If your supplier is a registered Limited Liability Partnership (LLP) you can search for their business registration number on MyLLP Customer Portal.
The Unique Entity Number (UEN) should be listed on the issued invoice. Here is an example of the information typically required on an invoice per IRAS.
If the UEN is not specified on your invoice, you may search for your supplier's UEN on this government data base. Your supplier must have a UEN Status that is 'REGISTERED' otherwise the platform will provide you with an error message.
TIP: If you can not find your supplier's detail it may be because their trade name is different than their registered name. For example, ipaymy is registered as 'IPAYMY TECHNOLOGIES PTE LTD,' so you have to try searching several variations of their name.