WhatsApp sales in Malaysia look deceptively simple: message a buyer, agree on price, send an invoice, collect payment. In practice, you're building a compliance problem in your phone. Most SMBs selling on WhatsApp in Malaysia skip the hard steps: validating a buyer's Service and Sales Tax (SST) registration, capturing their tax ID early enough to prevent invoicing delays, and maintaining a conversation log that survives an audit. The result is invoices that bounce back to accounting, tax returns that don't match your WhatsApp receipts, and payment records that disappear when someone leaves the team. This guide walks through a WhatsApp sales workflow that actually passes compliance. It's not complex—but it does require you to decide what data you capture and when, and which system stores it so accounting can find it later. Why WhatsApp sales need a formal compliance flow Malaysian tax authorities expect businesses to maintain a complete audit trail for every transaction. The definition of 'complete' includes: Proof that the buyer is a real business with an SST registration (if they should be registered) The invoice number, date, and amount Payment proof (bank transfer reference, date, amount) A record of who communicated with the buyer and when Evidence that the correct tax rate (0%, 6%, or service-specific) was applied Most WhatsApp-only workflows fail on the first and last items. You message a buyer without knowing their registration status, apply a tax rate based on what you assume, then later discover they're not registered or they're in an exempt category. The invoice has already gone out. Accounting has to reverse it. Your tax return shows the wrong number. The second problem is that WhatsApp conversations are private. If a team member leaves or their phone breaks, the entire thread—including price negotiations, agreed payment terms, and delivery dates—vanishes. Your accounting team has an invoice but no proof of what was actually agreed. Capture the tax ID before the first invoice Your WhatsApp sales process should ask for a buyer's tax ID or SST registration number in the first or second message, not the tenth. This is not optional paperwork—it's a gate. A buyer's registration status determines whether you charge SST at all: SST-registered buyer: You charge 6% SST and collect it on their behalf. They claim it back as input tax. Non-registered buyer (below RM500k annual turnover): No SST. Simpler, but you need proof they confirmed this status. Government agency or non-profit: Exempt. Different rules. You need their exemption reference. Asking 'What's your SST registration number?' in a WhatsApp message does two things: it signals that you run a formal business, and it screens for buyers who are serious or who can actually receive a compliant invoice. Store this number somewhere you won't lose it. If you're using a CRM , it should have a dedicated field on the company record. If you're using a spreadsheet or Notion, create a column. If you lose this number, you've lost your proof of due diligence. Validating the SST registration Once you have the number, validate it against the Royal Malaysian Customs Department's (RMCD) public register. This is free and takes two minutes. Go to sstonline.customs.gov.my , search for the business, and confirm: The registration number matches The business name matches the buyer's name The registration status is 'Active' The goods or services you're selling are in their registered scope Save a screenshot of the validation result. Screenshot, date, your name. This is your proof that you checked. If the number doesn't exist or the status is 'Suspended', stop. Do not invoice. Contact the buyer and ask for clarification. If they're genuinely non-registered, ask them to confirm in writing (WhatsApp message is fine) that they don't need SST. Keep that message. Use a system that logs conversations durably WhatsApp's built-in chat history is not an audit trail. It's a conversation that can be deleted, lost, or misread. If someone leaves your team, their phone takes the thread with them. The two approaches that actually work are: Export and store: Screenshot or forward key messages (price agreed, payment terms, tax ID confirmation) to an email account or shared storage. Date them. Use them as attachment reference on the invoice. Use a system that integrates WhatsApp natively: Tools like Orin's unified messaging system , Freshchat, or Respondio archive WhatsApp conversations in a searchable, tamper-proof format tied to the buyer record. Conversations don't disappear when a rep leaves. The second option is stronger for compliance because: The system timestamps every message automatically You can search by buyer, date, or content There's no ambiguity about who said what or when The log is separate from personal phones Accounting can access it without asking a sales rep If you're at five or fewer buyers, exporting to email works. If you're handling fifty conversations a month, you nee