You've registered with ACRA. You've got your UEN. But your CRM is empty, your spreadsheet is growing, and tax obligations are stacking up invisibly. Most solo founders in Singapore don't realize that audits start from your CRM data—not your accountant's summary. If your CRM doesn't enforce registration details, GST dates, and director duties from day one, you'll face friction during audit, missing data penalties, and hours of cleanup when tax season hits. Here's what actually matters before your first invoice: which data fields must live in your CRM, what validation rules prevent compliance gaps, and how to structure records so audits—and growth—don't break your system. Why CRM setup is a compliance gate, not a paperwork box ACRA doesn't audit based on what you tell them now. They audit based on what your operational records show 12 months later. If your CRM shows invoices before your GST registration date, or payroll records that don't match your director's duty declarations, or probation periods that don't align with CPF contributions—you're building an audit liability today. The reason most founders hit trouble: UEN is in their accountant's folder, but not in the CRM. Invoices get issued with the wrong entity name, and you're correcting them months later. GST registration date is known, but not enforced. You invoice GST retroactively, or you miss GST obligations on the first month. Probation periods for first employees are tracked in email, not in your payroll system. CPF contributions start on day 1, violating MOE rules. Director duties (conflict of interest, related-party transactions) are never recorded, so auditors see transactions without context. Audit penalties in Singapore: $5,000–$10,000 for missing payroll records, $500–$2,000 for GST misalignment, plus 40+ hours of remediation per finding. Most penalties are preventable with CRM structure. Core data fields that must live in your CRM from day one Your CRM isn't just a sales tool—it's your audit trail. These fields must be present and validated before you process your first transaction: Company and entity fields UEN (Unique Entity Number) : 9 or 12 characters, validated against ACRA format. Every invoice, receipt, and contract must reference the correct UEN. Store this at the company level, not per invoice. Registered business name : Exact spelling as per ACRA. Auto-populate on all customer-facing documents. Mismatches with invoices = audit flags. ACRA registration date : The date ACRA issued your certificate. This is your operational start date for GST, payroll, and tax purposes. Business address (registered and operational) : If they differ, both must be in the system. Auditors verify correspondence against the registered address. GST and tax fields GST registration date : Not optional. GST applies if you exceed $1M in turnover within 12 months, or if you register voluntarily. Lock this date and prevent invoices from being issued before it. Validation rule: invoice date must be ≥ GST registration date if invoice includes GST . GST registration number (if applicable) : Format is 10 digits. Store separately from UEN. Last GST filing date : Track for internal reminder, not CRM enforcement, but useful for audit prep. Tax residency declaration : Required for LHDN/regional tax purposes if you have cross-border clients. Store once, reference in contract templates. Payroll and director fields Director name(s) and NRIC : Exactly as on ACRA. Required for MOE filings and tax returns. Match against shareholder list to catch discrepancies. Director appointment date : Day ACRA approved. Transactions before this date are invalid if they rely on director authority. First employee start date and probation end date : Probation is capped at 3 months (or 6 months for certain roles). CPF contributions must not start until probation ends. Store probation_end_date and enforce payroll cutoff. Validation rule: CPF contribution ≥ probation_end_date . Related-party transaction flag : Mark any deal, invoice, or contract involving directors, family, or related companies. Auditors will ask; pre-flagged records save hours. Validation rules that prevent audit friction Data fields are useless without rules. Your CRM should reject or warn on these scenarios: Invoice validation Invoice date before UEN issue date: reject. Invoice includes GST but is dated before GST registration: reject or flag for manual approval. Invoice issues to a director before director appointment date: warn. GST amount is calculated but GST registration status is "not registered": reject. Payroll validation Employee CPF contribution before probation_end_date: reject with reason. Monthly salary entry without corresponding contract on file: warn. Contract missing probation clause: flag during employee creation. Related-party transactions Invoice to director or spouse: auto-flag and require approval comment. Related-party transaction over $10,000: require director sign-off in CRM (not email). Mapping this t