AI agents for finance: the skills, the job and the agent
Most finance teams use AI one question at a time: explain this variance, tidy this table, draft this reminder. Everyone asks in their own way, and nobody can check afterwards what the answer was built on.
There is a better way, and it is a ladder with three rungs. A skill writes down one task the way your best accountant does it. Several skills in order make a job, with someone checking each step. The job running on its own, stopping for a person before anything is booked or leaves the house, is an agent. Below is that ladder for finance and accounting, from the first skill to the agent.
- 01
6 skills
One task each, described in detail.
- 02
Connectors
Reach into the systems the tasks need.
- 03
One job
Preparing the month-end close
- 04
One agent
The close prep agent
Claude skills for finance: the 6 to write first
month-end-close-checklistMonth-end close checklist
Use when: the month is closing or someone asks what is left before the books can be closed.
Goes through the close list (bank reconciliation, supplier invoices, accruals, prepayments, payroll, VAT) against what it is given, marks each item done or open, and puts an owner and a date on every open item.
Output: A close status on one page, with the open items first.
month-end-accrualsMonth-end accruals
Use when: costs need to be accrued at month-end, last month’s accruals need reversing, or someone asks what to accrue.
Compares supplier invoices with contracts and last month’s accruals, and proposes each accrual with amount, account, cost centre and the source behind it.
Output: A list of proposed accruals for the controller to approve and book.
supplier-invoice-codingSupplier invoice coding
Use when: a batch of supplier invoices needs an account, cost centre and VAT code before approval.
Suggests account, cost centre and VAT code for each invoice from the coding rules and earlier invoices from the same supplier, and flags anything unusual: a new supplier, new bank details, an amount far above normal.
Output: A coding table with one row per invoice and the flagged ones on top.
vat-reconciliationVAT reconciliation
Use when: the VAT return is due or someone asks whether the VAT adds up.
Compares the VAT on customer and supplier invoices with the VAT accounts for the period, lists every difference with the invoice behind it, and says what to check before the return is filed.
Output: A reconciliation where every difference is explained or marked for checking.
overdue-invoice-follow-upOverdue invoice follow-up
Use when: it is time for the weekly run through overdue customer invoices, or someone asks who owes us money.
Groups overdue invoices per customer, picks the next step from the reminder rules (friendly reminder, firm reminder, phone call) and drafts each message with invoice number and due date.
Output: A list of customers to chase, each with a draft or a suggested call.
variance-commentaryMonthly variance commentary
Use when: the monthly management report needs its commentary or someone asks why a number moved.
Compares the month with budget and last year, explains every variance above the agreed threshold with its source, and writes the commentary in the board’s format.
Output: Half a page of commentary the CFO can sign off.
What a good skill looks like
An example written for this page, following Anthropic’s guidance for writing skills. Adapt it to how your team works.
---
name: month-end-accruals
description: Proposes month-end accruals and prepayments, with a source for every amount. Use when the month is closing, someone asks what to accrue, or last month’s accruals need reversing.
---
# Month-end accruals
## What you deliver
One table and three short lists, in this order: Proposed accruals, Reversals, Prepayments, Missing data.
Each accrual row: supplier, what it is for, period, amount, account, cost centre, source.
## Steps
1. Get the supplier invoices dated in the closing month and the two months before, last month's accruals file and the list of contracts.
2. Find the suppliers who invoice every month. If this month's invoice has not arrived, propose an accrual.
3. Take the amount from the contract or purchase order. If there is none, use last month's invoice for the same service and say so.
4. Go through unbooked invoices dated after month-end. If the work was done in the closing month, propose an accrual.
5. Reversals: match each of last month's accruals with the invoice that has now arrived. If none has, keep the accrual and say why.
6. Prepayments: flag every invoice that covers more than one month (rent, licences, insurance) and split it per month.
## Rules
- Every amount needs a source: an invoice number, a contract or a file name. No source, no amount.
- If you cannot find a source, list the supplier under Missing data with what to ask and who to ask.
- Never round up to be safe. Never average several invoices unless the controller has asked for it.
- Take account and cost centre from the coding rules. If the rules do not cover a case, write "Ask".
- You propose. A person approves and books.
## Example
Acme Facility AB invoices office cleaning every month. The May invoice has not arrived by 3 June.
Proposed accrual: office cleaning, May, the monthly fee in contract AF-2024-03, account 5060, cost centre 100. Source: contract AF-2024-03, invoice not received.
- The description covers reversals too
- Claude reads only the name and description until a task matches. People ask “what do we accrue?” but also “can we reverse May?”, so the description names both moments.
- No source, no amount
- An invented accrual looks exactly like a real one. The rule makes every number checkable and turns every gap into a question with a name next to it.
- It proposes, a person books
- The last rule matches how the agent works: it reads Fortnox, Visma or Xero and cannot book anything. The controller approves every line.
From skills to a job: Preparing the month-end close
Today the controller spends the first two days of the month finding out what is missing. With the skills and the right connectors, that list is ready in the first hour, in Claude or ChatGPT, and the days go to the close itself.
- 01Ask the AI for last month’s unbooked supplier and customer invoices from Fortnox, Visma eEkonomi or Xero.
- 02Run supplier-invoice-coding on the unbooked supplier invoices.
- 03Run month-end-accruals with last month’s accruals file and the contracts.
- 04Run month-end-close-checklist to get the open items, owners and dates.
- 05Check every proposed accrual and coding against its source, then book them yourself.
From job to agent: The close prep agent
The first working day of every month at 06:00.
- 01Fetches supplier invoices from the last three months and every invoice still unbooked. via Fortnox MCP
- 02Searches the inbox for supplier invoices that have not reached Fortnox yet. via Outlook MCP
- 03Reads the close checklist and last month’s accruals file. via SharePoint MCP
- 04Runs supplier-invoice-coding on the unbooked invoices, then month-end-accruals and month-end-close-checklist.
- 05Posts the close status and the proposed accruals in the finance channel for approval. via Microsoft Teams MCP
The controller checks every proposed accrual and coding against its source, corrects what is wrong and books it in Fortnox. The agent cannot book: the connector only reads. Nothing is booked before a person has approved it.
A close status with open items, owners and proposed accruals in the finance channel before nine on the first working day, every month.
In Claude, make the close prep a scheduled task: describe the job once, choose a monthly cadence, and it runs with your skills and connectors even when your laptop is closed. Scheduled tasks are on every paid Claude plan. In ChatGPT Work, a scheduled task does the same on the same cadence.
With Deployed OS, the skills and the Fortnox, Visma or Xero connector belong to the company. Each person connects with their own login, so the AI sees only what that person may see in the accounting system. Admins decide which groups may let the AI write anywhere, and every call the agent makes is logged.
Where it goes wrong
- Automating the close too early
- Run the close by hand with the skills for two or three months first. Month-end comes twelve times a year, so each run is a chance to find the missing rule while a person is still watching.
- Approving the summary, not the lines
- A controller who approves the close status without opening the sources has approved a guess. Check each accrual against the invoice or contract it names, at least for the first months.
- Coding rules in one head
- If only your most senior accountant knows which account a cost goes to, the skill will make up its own rules. Write the coding rules down first. That alone is worth the work.
- Trusting new bank details
- A supplier invoice with new bank details is a classic fraud. The coding skill should flag it every time, and a person should confirm the change by phone, never by replying to the email.
AI agents for finance: common questions
The recurring work with clear rules: preparing the month-end close, proposing accruals, coding supplier invoices, chasing overdue invoices, drafting the variance commentary. It prepares; a person approves and books. It reads your accounting system and changes nothing in it.
Start where the rules already exist, even if only in one person’s head: the close checklist, supplier invoice coding or the reminder levels for overdue invoices. Write one, use it through a full month-end, fix what it got wrong, then write the next.
No. The Fortnox, Visma eEkonomi and Xero connectors only read customers, customer invoices and supplier invoices. Nothing is booked, created or sent there. In Gmail and Outlook the agent can create drafts, which are never sent, and in Slack or Teams it can post a message. We recommend that a person approves and books every accrual and sends every customer email. With Deployed OS, admins decide which groups may let the AI write in any system at all.
Either works. A skill is plain text, and through Deployed OS the same skills and the same Fortnox, Visma or Xero connector work in Claude, ChatGPT and Copilot. Pick the assistant the team already uses.
Only if the skill makes them checkable. Write it so every amount names its source: an invoice number, a contract, last month’s file. The agent reads your accounting system and cannot change it, so the books stay yours. With Deployed OS every call the agent makes is logged, so you can see afterwards what it read and when. Deployed is an EU company, and you choose where the data is stored, down to the city.
It depends on the size of your team. Get in touch and we will walk you through it.
Start with one job.
Tell us which task eats your team’s week. We’ll show you the skills that do it, and the agent that runs it.
