Using dimensions on a sales document in Business Central

Dimensions are the tags — department, project, region, cost centre, whatever categories your business tracks — that let Business Central slice the same set of accounts multiple ways in reporting. If your company uses them, you'll see one or two dimension columns on every sales and purchase document line, usually already filled in.

Where they show up

On a sales or purchase document line, dimension fields appear as extra columns (you may need to use the column chooser to show them if they're hidden) or via the Dimensions action on the line, which opens the full set for that line.

Steps

1. Check what's already defaulted. Add a line with a customer and item selected — dimension values often populate automatically from the customer card, item card, or the salesperson assigned to the document.
2. Open the full dimension set if you need to see everything. Select the line, then Line > Dimensions (or the dimensions icon), to see every dimension assigned to that line, not just the one or two shown as shortcut columns.
3. Override a value when the default is wrong for this transaction. Click into the dimension field and pick a different value from the list — for example, a shared expense that should be split against a specific project rather than the customer's usual department.
4. Set a document-level default before adding lines, if every line on this invoice should carry the same dimension value — set it on the header and it flows to new lines added afterward (it does not retroactively change lines already entered).
5. Resolve a blocking error. If posting is refused with a dimension-related message, go back to the flagged line, open its dimension set, and fill in whatever's required — the error message usually names the missing dimension.
6. Post as normal. Dimensions travel with the posted entry and are what your finance team filters by later in account schedules and analysis views.

What you need

Setting up new dimensions or dimension defaults is normally an administrator or finance-configuration task; using dimensions that are already set up on a document requires no special permission beyond the ability to create that document type. Check current licensing and role setup with your administrator if dimension fields are missing entirely from your screen — they may be hidden by a page personalisation rather than genuinely absent.

Limits and gotchas

• A blank dimension isn't always an error — until it is. Whether a missing dimension blocks posting depends on your company's dimension value posting rules; some businesses require certain dimensions and leave others optional.
• Defaults can be wrong for the transaction at hand. A customer's default department is a starting point, not a guarantee — check it on anything unusual, like a one-off project sale, before posting.
• Dimension combinations, not just values, can be restricted. Some setups block specific pairs (a department and a project that shouldn't co-occur) even if each value is individually valid.
• Correcting a posted entry's dimension is not the same as correcting a document field — talk to finance before assuming a quick edit is possible; in many companies it isn't, by design, to protect reporting history.

Why finance teams care so much about this

A missing or wrong dimension rarely breaks anything visible to the person entering the document — the invoice posts, the customer gets billed, everything looks fine on the surface. The damage shows up weeks later, when someone in finance runs a departmental profit report and a chunk of revenue or cost sits in an "unassigned" bucket because a line was posted without the department dimension filled in. That's why some companies make certain dimensions mandatory for posting even though it occasionally slows down document entry — the alternative is a finance team spending hours every month reallocating misclassified transactions by hand. If you're ever tempted to leave a dimension blank because you're not sure which value applies, it's worth the thirty seconds to ask rather than guess or skip it.

Dimensions show up on both sides of the ledger — see How to post a sales invoice in Business Central and How to create a purchase order in Business Central for the documents where you'll meet them most often.