Number sequences in Dynamics 365 Finance and SCM

Dynamics 365 Finance and SCM generates unique identifiers — voucher numbers, document numbers, master-record IDs — through a number sequence framework that's more elaborate than Business Central's. Understanding its scope and operating mode matters for statutory compliance, performance, and avoiding the silent gaps that can become audit findings.

The model. A number sequence has:

• A code — the identifier of the sequence.
• A scope — Shared, Company, Legal entity, Operating unit. Determines whether different companies share or have separate sequences.
• A segmentation — the structure of the generated number, combining alphanumeric prefixes, constants, and the numeric counter.
• A counter range — first, last, current, format.
• Continuous or non-continuous — see below.
• Manual entry allowed — whether users can override the auto-generated number.
• Allow changes — whether the sequence definition can be edited after use.

Segmentation. A number sequence's output is built by concatenating segments. Examples:

• INV-{0000000000} — produces INV-0000000001, INV-0000000002, etc.
• {Year}-{Company}-{0000000} — produces 2026-FIN-0000001, 2026-FIN-0000002.
• Year and company segments are dynamic and re-evaluated at each generation.

Different segmentations can be applied per scope or per condition (e.g. invoice prefix per legal entity).

Continuous vs non-continuous.

• Continuous — the sequence guarantees no gaps. Each number generation reserves a number; if the using transaction fails to commit, the number is not released — but the system tracks reservation and uses sophisticated handling to minimise gaps. Continuous sequences are statutorily required in many jurisdictions for posted document numbering (especially invoices), and the trade-off is performance: continuous sequences serialise number generation, causing locks at high concurrency.

• Non-continuous — the sequence trades gap-freeness for performance. Numbers are allocated in batches per user/session; gaps appear if a session ends without consuming all reserved numbers. Acceptable for internal-only document numbering where gaps are immaterial.

Choose continuous for any externally-visible, statutorily-relevant numbering (sales invoices in EU jurisdictions, e-invoicing references, customer-facing PO numbers). Choose non-continuous for high-volume internal numbering (journal voucher numbers, item ledger entries) where performance matters more.

Manual override. Most number sequences allow manual entry where the auto-generated number can be overridden. Useful for migration; risky in steady-state because it allows user-controlled gaps and duplicates. Tighten to "automatic only" after go-live wherever statutory compliance allows.

Per-company vs shared. Set the scope carefully:

• Shared — the same sequence across all companies in the tenant. Used for cross-company references.
• Company — separate sequence per company. Used for company-internal numbering.
• Legal entity — separate per legal entity. The most common.

Renaming and resetting. Once used, sequences should not be reset or restructured — historical references in audit trails depend on the existing numbering. Plan for several years of growth in the initial range.

Operational pitfalls.

• Reaching the upper bound. A sequence configured 1–999999 hits the wall after a million transactions. Configure realistic ranges with year prefixes that segment naturally.
• Statutory gap-free requirement missed. Setting an invoice sequence non-continuous in a country that requires gap-free invoicing triggers audit findings. Verify country requirements.
• Performance lock under load. Continuous sequences serialise; high-concurrency transactional environments need careful tuning.

Audit. Every generated number is logged; gaps in continuous sequences are investigable.