Instructing agents on booking accounts

Matching guidelines tell Cortena where the rules live. This article explains how to write them so the matching agent behaves like a well-briefed junior bookkeeper, especially when your chart of accounts is large or ambiguous.

Who this is for: Finance leads and controllers who maintain the Chart of Account Matching Guide and chart-of-accounts spreadsheet, and want fewer Needs review invoices and fewer verification corrections.

Start from Settings → Accounting Preferences → Matching Guidelines & Instructions. Pair this with Matching guidelines for document setup, and Matching correction for how Cortena resolves uncertain matches.

1. Brief the agent like a junior bookkeeper

Cortena's matching agent has never sat with your team. It only knows what you write down.

Write instructions the way you would onboard an intern on day one:

• How vendors are booked · by supplier name, by invoice type, or by what the line means
• How line items are read · description, product category, and business meaning (not only the raw text)
• What "always" means for your company · exceptions and one-offs called out explicitly
• What to do when unsure · prefer a specific account, escalate to Needs review, or apply a named default

Vague guidance produces vague matches. Explicit, concrete guidance produces stable booking codes.

If a new hire who has never booked for you could not decide from your text alone, the agent probably cannot either.

2. Chart of Account Matching Guide (the strong layer)

The Chart of Account Matching Guide (Google Doc) is the conceptual instruction set: what to book how and where.

Use it for:

1. Concepts · for example, "Wood and timber deliveries are cost of goods / Wareneingang, not office supplies."
2. Category rules · for example, "Software subscriptions and cloud licenses → IT / license expense."
3. Reinforcement after a miss · very specific rules such as "Always book Supplier X line items to account Y," or "Never book fuel from Tankstelle Z to travel; use fleet / vehicle costs."

This document is the strongest place for hard rules. When quorum is unstable or the verification agent has to step in, clarifying or adding a rule here is usually the fix.

3. Chart of accounts spreadsheet (guiding, not as strong)

The Chart of Accounts spreadsheet guides the agent with account labels and optional context columns. You can enrich rows with examples and supplier hints, for example:

• "Always book wood delivery as cost of goods sold / Wareneingang"
• Short lists of typical invoice wording under an account
• Optional hints for specific suppliers on a row

These enrichments help a lot, especially on large charts, but they are a weaker signal than an explicit rule in the Matching Guide. Prefer:

• Spreadsheet · examples, synonyms, "typical use" notes next to accounts
• Matching Guide · hard "always / never / for supplier X use Y" policies and conceptual splits

If a supplier-specific hint in the sheet is still ignored or competed with by another account, promote it into the Matching Guide as a firm rule.

4. Do and don't when instructions are ambiguous

Do

• Name accounts with codes and plain labels (for example 5400 Consulting and 6837 Licenses)
• Describe line meaning, not only supplier brand ("cloud hosting" vs "Microsoft")
• Split look-alike categories with a short contrast ("stationery vs warehouse packaging")
• State priority when two rules could apply ("supplier rule beats generic category")
• Add a reinforce rule after every recurring correction you make by hand

Don't

• Write only "book correctly" or "use the usual account"
• Leave two overlapping accounts with the same example wording and no tie-breaker
• Rely only on spreadsheet hints for a supplier that must never deviate
• Assume the agent knows your industry jargon without defining it
• Stack contradictory rules across Doc and sheet without saying which wins

5. How Cortena decides: quorum and the supervising agent

Cortena uses quorum-based matching: the matching agent proposes a booking account several times for the same line and looks for enough agreement on one code.

• When a stable quorum is found → that account is used.
• When no quorum is found, or the quorum is unstable (candidates keep disagreeing) → a supervising / verification agent reviews the line and makes a final choice, with a short rationale you can see on the invoice.

That supervised step is valuable, but it most often fires because the booking instructions were ambiguous or incomplete. Think like a human manager: what would you need to write so someone who has never booked for you picks the same account every time?

Details of purple highlights, tooltips, and majority fill: Matching correction.

6. Most matching issues are ambiguity

In large chart-of-account setups, many accounts look plausible for the same line. That is the main source of:

• Missing booking accounts
• Unstable quorum
• Frequent verification corrections
• Recurring Needs review

The remedy is clearer instructions: concepts in the Matching Guide, examples in the spreadsheet, and hard supplier rules where needed. Not more manual rework forever.

If you share typical misses or a complex CoA, Cortena can help you structure the Guide and sheet so the agent converges. White-glove onboarding is available when you want a structured pass over your rules.

7. Practical writing checklist

1. Open Settings → Accounting Preferences → Matching Guidelines & Instructions.
2. Skim recent Needs review / purple verification accounts. Each pattern is a missing or weak rule.
3. Add or sharpen a conceptual rule in the Chart of Account Matching Guide.
4. Enrich the CoA spreadsheet with examples (and light supplier hints if useful).
5. Promote stubborn supplier cases into always / never Guide rules.
6. Reprocess a sample invoice (or wait for the next one) and confirm the match is stable.

Quick reference