Stop the leak: 10 AI skills for what your suppliers charge you
credit-chase
find the credits you were promised and never got
How the two work together
Claude thinks it through. Paste the Claude prompt into Claude Code, or drop the folder into your skills folder. Claude does the judgement: what to look for, what is worth doing, what is right.
Codex gets it done. At the hand-off point Claude runs Codex on your machine with one command and passes it the Codex prompt. Codex does the mechanical part and hands the result back. Claude checks it before you see it.
No API key to set up: Claude calls the Codex you already have installed. If Codex is not installed, Claude does that half itself and tells you.
Prompt for Claude
--- name: credit-chase description: Finds the credit notes a supplier agreed to and never sent, checks each one against your delivery notes, invoices and statements, and drafts the chase email with the evidence attached. Use when you think a supplier owes you money for short deliveries, damaged goods, returns or wrong prices. --- # Get back the credits your suppliers promised you You hand over your supplier statements, the purchase invoices for the same period, your delivery notes (including the ones with writing on them or a photo attached), and any emails or messages where someone said a credit was coming. You get back a numbered schedule of every credit that was promised and never arrived, valued in pounds with the VAT shown separately, and a chase email per supplier with the evidence attached and a date to reply by. ## What it does 1. **Take one supplier at a time and gather the four record sets.** Ask for the supplier's name and account number, the period being checked, and then four things: every statement covering that period, every purchase invoice from that supplier, every delivery note or goods received note, and an export of that supplier's account from the bookkeeping software or the bank. Do not start on a second supplier until the first is finished and sent. A schedule that mixes two suppliers cannot be sent to either of them. 2. **Agree the opening balance before touching anything else.** Take the opening balance on the earliest statement in the period and compare it with the balance on that supplier's account in the books on the same date. If they differ, write the difference down as a single figure and carry it forward as an unexplained opening difference rather than trying to fix it. Michael Brown of Double Entry Bookkeeping sets the order as: agree opening balances, mark matching items between statement and ledger, allocate credit notes and payments against invoices, then identify what is left. Follow that order. 3. **Build one table with a line for every transaction.** Columns: date, document type (invoice, credit note, payment), document number, purchase order number, delivery note number, net, VAT rate, VAT, gross, on our ledger (yes/no), on the statement (yes/no). Fill it from the statements first, then tick off from the invoices and the ledger export. Tipalti describes the underlying control as "the process of comparing the purchase order, invoice, and goods receipt to make sure they match, prior to approving the invoice" — this table is that comparison written down so it can be sent to someone. 4. **Harvest every promise of a credit into a separate schedule.** Read the delivery notes for handwriting and driver signatures, the invoices for crossings-out and amended quantities, and the emails and messages for the words credit, credit note, CN, refund, sort that out, or take it off. Jelly's guide to restaurant credit notes describes the receiving habit this depends on: "Staff photograph the issue, note it on the invoice, and obtain the driver's co-signature on the spot rather than relying on later documentation." For each promise record: date promised, the name and job title of whoever promised it, exactly where the promise lives (file name, photo name, email subject and date), the delivery note number, the invoice it relates to, the goods, the quantity, the unit price, the net value, the VAT rate and the gross. 5. **Match each promise to a credit note and give it one of three states.** RECEIVED AND APPLIED means a credit note exists, it names the original invoice, and it has been posted to the account. RECEIVED NOT APPLIED means the credit note exists but the money is still sitting unused — that one is yours to fix today, not a chase. NEVER RECEIVED means no credit note exists at all. Match on the original invoice number, not on the amount, because two short deliveries of the same case will produce the same figure twice. 6. **Rule out a timing difference before calling anything missing.** A credit note raised near the statement date will land on the next statement and needs no chase. Michael Brown separates those from omissions and errors, which are "not due to timing, and will not correct itself in a later accounting period". The test: an item missing from two consecutive statements is an omission, not timing. If only one statement has been supplied, say so on the schedule and mark those rows UNCONFIRMED rather than chasing them. 7. **Value each gap in net and VAT separately and set the listing floor.** Show net, VAT rate, VAT and gross on every row. This matters because the credit changes your VAT return, not just your bill — HMRC's guidance on changes in consideration states that "For decreases in VAT, VAT registered customers must reduce the amount of VAT they have claimed by the same amount." Chase every row of £5 or more individually. Pool anything under £5 into one appendix line, and if that pool is over £50 flag it to the owner as a pricing or delivery pattern rather than small change. 8. **Write one chase email per supplier with the schedule in the body and the evidence attached.** Subject line: supplier account number, the words credit notes outstanding, the period, and the gross total. Body: two sentences, then the numbered table, then one ask. The ask is a single sentence naming a date fourteen days out and what you want by it — credit notes issued against the listed invoice numbers, or a written reason each one is refused. Name every attachment in the row it belongs to, so row 3 says "see DN-4471.jpg" and that file is in the pack. Do not put the VAT 14-day rule in the first email: HMRC's guidance says "the 14 day time limit for issuing this starts once the refund has been made to the customer", and most hospitality credits are offsets against the next payment rather than refunds, so quoting the deadline at the wrong moment hands the supplier an easy correction. 9. **Set the follow-up ladder and list the decisions only the owner can make.** Day 0 to the supplier's accounts or credit control address. Day 7 to the named account manager, same schedule, one line asking which rows are disputed. Day 14 a call, then the same schedule again by email with a note of what was said and who said it. Finish with a short decision list for the owner: which rows to write off, which to escalate, and whether to withhold any disputed amount from the next payment run. Withholding money is the owner's decision and is never taken in the draft. ## Then it checks 1. Every row on the schedule names a source document, and every document named exists in the files the owner supplied — no row cites evidence that was not provided. 2. Every net, VAT and gross figure on a row can be traced to a named file, and the schedule total equals the sum of the rows to the penny. 3. No row says a credit was agreed unless the schedule carries the words of the promise and the name of the person who made it. 4. Every row carries exactly one of the four states: RECEIVED AND APPLIED, RECEIVED NOT APPLIED, NEVER RECEIVED, UNCONFIRMED. 5. The gross total in the chase email matches the schedule total, and every attachment named in the email is in the pack. 6. Net and VAT are shown separately on every row, and no row claims the supplier has missed the 14-day credit note deadline unless a refund date is recorded on that row. Any check fails: name it, redo that step once. Failed twice: say what is wrong and stop. ## Rules - Public information only. - Never invent a fact, a number or a quote. - Never invent a credit note number, a delivery note number, an invoice number or a date. A chase schedule with one reference the supplier cannot find gets the whole schedule set aside, and the real rows are lost with the fake one. A blank marked UNTRACED is worth more than a plausible guess. - Never turn "I'll look into it" into "agreed". Anything short of a stated amount or a stated credit is recorded as raised, not agreed. Claiming an agreement that did not happen is the one thing that loses an argument you were winning. - Never tell the owner to deduct a disputed amount from the next payment run. Put it on the decision list with the figure and the reason. Short-paying a supplier without deciding to is how a delivery gets stopped mid-service. - This is a working document prepared for the owner's accountant or bookkeeper to check before any credit is posted or any VAT return is adjusted. HMRC's trader records manual is explicit that "the VAT liability is determined by the underlying supply position, not by the issue or receipt of a credit note", so nothing here is VAT advice and nothing here is a substitute for the accountant signing it off. ## Built from - HMRC, "VATSC06635 - Consideration: Change in consideration: Changes to Regulation 38 from 1 September 2019", https://www.gov.uk/hmrc-internal-manuals/vat-supply-and-consideration/vatsc06635, no publication date shown on the page, read 13 September 2026: the 14-day credit note deadline and the fact that it starts when a refund is made, plus the customer's duty to reduce input VAT already claimed. - HMRC, "VATREC13020 - Credit and Debit notes: Legal basis", https://www.gov.uk/hmrc-internal-manuals/vat-trader-records/vatrec13020, no publication date shown on the page, read 13 September 2026: the principle that VAT follows the underlying supply rather than the piece of paper, which is why the schedule records the goods and the delivery note, not just the credit note. - Michael Brown, "Supplier Statement Reconciliation", Double Entry Bookkeeping, https://www.double-entry-bookkeeping.com/accounts-payable/supplier-statement-reconciliation/, last updated 17 December 2019: the four-step order of work in step 2 and the distinction in step 6 between a timing difference and an omission that will never correct itself. - Tipalti, "What is a 3-Way Match? How It Works in the AP Process", https://tipalti.com/resources/learn/3-way-match/, last updated 28 July 2026: the fields compared across purchase order, goods receipt note and invoice, which became the columns of the transaction table in step 3. - JJ Tan / Jelly, "Supplier Credit Notes for UK Restaurants: Full Guide", https://blog.getjelly.co.uk/supplier-credit-notes-restaurant/, published 25 August 2026, updated 4 September 2026: the hospitality receiving habits that create the evidence in step 4 — photograph, annotate the invoice, get the driver's signature at the door.
Prompt for Codex
# credit-chase ## You are given A folder from a UK hospitality business covering one supplier: the statements for a stated period, every purchase invoice from that supplier, the delivery notes and goods received notes (including photographs of annotated ones), an export of that supplier's account from the bookkeeping software or the bank, and any emails, WhatsApp exports or texts where somebody said a credit was coming. The supplier name, account number and the period are supplied in a text file. Assume the delivery notes are photographs with handwriting on them, the statement is a PDF, and the ledger export and the statement do not agree. ## Produce Write into an `output/` folder next to the inputs: 1. `transaction-table.csv` with these columns in this order: `Date`, `Document type` (invoice, credit note, payment), `Document number`, `Purchase order number`, `Delivery note number`, `Net (GBP)`, `VAT rate`, `VAT (GBP)`, `Gross (GBP)`, `On our ledger` (yes/no), `On the statement` (yes/no), `Source file`. One row per transaction, built from the statements first and then ticked off against the invoices and the ledger export. 2. `opening-balance.md` - the opening balance on the earliest statement, the balance on the supplier's account in the books on the same date, both with their source file names, and the difference as a single figure headed `Unexplained opening difference`. Do not try to resolve it. 3. `credit-schedule.csv` with these columns in this order: `Row`, `Date promised`, `Promised by (name)`, `Job title`, `Where the promise lives` (file name, photograph name, or email subject and date), `Words of the promise (verbatim)`, `Delivery note number`, `Original invoice number`, `Invoice date`, `Goods`, `Quantity`, `Unit price net of VAT (GBP)`, `Net (GBP)`, `VAT rate`, `VAT (GBP)`, `Gross (GBP)`, `State`, `Evidence file`. `State` holds exactly one of: `RECEIVED AND APPLIED`, `RECEIVED NOT APPLIED`, `NEVER RECEIVED`, `UNCONFIRMED`. Sort by `Gross (GBP)`, highest first. 4. `under-5-pool.csv` with columns: `Row`, `Date promised`, `Original invoice number`, `Goods`, `Net (GBP)`, `VAT (GBP)`, `Gross (GBP)` - every row under £5 gross. Write the pool total at the foot. 5. `untraced.csv` with columns: `What is missing`, `Row it belongs to`, `Original invoice number if known`, `What was looked for`, `Where it was looked for`. 6. `chase-email-<supplier-slug>.md` - one file per supplier. Subject line: the account number, the words `credit notes outstanding`, the period, and the gross total. Body: two sentences, then the numbered table taken from `credit-schedule.csv` showing only `NEVER RECEIVED` and `UNCONFIRMED` rows, then one sentence naming a date fourteen days from today and asking for credit notes against the listed invoice numbers or a written reason each one is refused. Every attachment is named in the row it belongs to. 7. `evidence/` - a folder holding a copy of every file named in the schedule or the email, named to match the reference used in the row. 8. `follow-up-ladder.csv` with columns: `Day`, `Date (DD Month YYYY)`, `Who it goes to`, `Channel`, `What is sent`. Three rows: day 0, day 7, day 14. 9. `decisions-for-the-owner.csv` with columns: `Row`, `Original invoice number`, `Gross (GBP)`, `Age in days`, `Decision needed`, `Facts behind it`. The `Decision needed` column states the choice only. It never states a recommendation. 10. `README.md` - the files read, the statement date range, the number of rows in each state, and what could not be traced. ## Rules - One supplier per run. Never build a schedule that mixes two suppliers; it cannot be sent to either of them. - Every row names a source document, and every document named must exist in the folder supplied. Never cite evidence that was not provided. - Never invent a credit note number, a delivery note number, an invoice number or a date. A blank marked `UNTRACED` in `untraced.csv` is the correct output; a plausible guess is not. - Match a promise to a credit note on the original invoice number, never on the amount. Two short deliveries of the same case produce the same figure twice. - Never record a promise as agreed unless the row carries the words of the promise and the name of the person who made it. Anything short of a stated amount or a stated credit is recorded as raised, not agreed. - An item missing from two consecutive statements is an omission. An item missing from one is `UNCONFIRMED`. If only one statement was supplied, every candidate row is `UNCONFIRMED`. - Show net and VAT separately on every row. Purchase figures go in net of VAT and are labelled as such. The schedule total must equal the sum of the rows to the penny, and the gross total in the email must equal the schedule total. - Never write that the supplier has missed the 14-day credit note deadline unless that row carries a recorded refund date. Do not put the deadline in the first email. - Never tell the owner to deduct, withhold or short-pay anything. That goes in `decisions-for-the-owner.csv` as a figure and a reason. - Never calculate statutory interest, late payment compensation or any entitlement under the Late Payment of Commercial Debts (Interest) Act. Add no interest figure, no daily rate and no fixed sum to any row or email. - Round nothing except at the point of display, to two decimal places. - Use British English, £, and DD Month YYYY dates. No em dashes. - The output is a working document prepared for the owner's accountant or bookkeeper to check before any credit is posted or any VAT return is adjusted. Write no sentence about VAT treatment beyond showing the rate and the amount. ## Return A list of the files written with their absolute paths, the count of rows in each of the four states, the gross total of the `NEVER RECEIVED` rows, the pool total of the under-£5 rows, the unexplained opening difference, and every row that carries a promise with no named person.
Built from the best public work on this
Sources for credit-chase
Everything below was opened and read on 13 September 2026. Nothing is cited that could not be loaded.
1. HMRC, "VATSC06635 - Consideration: Change in consideration: Changes to Regulation 38 from 1 September 2019"
https://www.gov.uk/hmrc-internal-manuals/vat-supply-and-consideration/vatsc06635, no publication date shown on the page, read 13 September 2026.
This is HMRC's own internal manual for its staff, covering what happens to VAT when the price of a supply changes after the invoice has gone out. It is the legal spine of this skill. Two lines drive the design. First: "A credit note must be issued to the customer to reflect the decrease and the 14 day time limit for issuing this starts once the refund has been made to the customer." Second: "For decreases in VAT, VAT registered customers must reduce the amount of VAT they have claimed by the same amount." The first is why step 8 tells the owner not to lead the chase email with the 14-day rule. A restaurant almost never gets a refund from a drinks wholesaler; it gets a credit offset against the next delivery, so the clock the owner thinks is running usually is not, and quoting it wrongly lets the supplier win the first exchange on a technicality. The second is why every row of the schedule splits net from VAT: an unclaimed credit is not only money owed, it is also input VAT the business may have over-recovered, and the accountant needs to see the two figures apart to know what to do with the return.
2. HMRC, "VATREC13020 - Credit and Debit notes: Legal basis"
https://www.gov.uk/hmrc-internal-manuals/vat-trader-records/vatrec13020, no publication date shown on the page, read 13 September 2026.
A short page in HMRC's VAT Trader Records manual setting out where credit notes sit in law. The sentence taken from it is that "the VAT liability is determined by the underlying supply position, not by the issue or receipt of a credit note." That single idea changed the shape of the skill. The obvious way to build a credit chase is to hunt for missing credit notes, which means hunting for a document. HMRC's point is that the document is the record, not the event. So the schedule in step 4 is built around the underlying event — the short case, the damaged box, the price that did not match the agreed rate — evidenced by the delivery note and the photograph, with the credit note recorded as present or absent against it. A supplier can argue about a missing piece of paper. It is much harder to argue with a signed delivery note showing eleven cases where twelve were invoiced. Note also the earlier URL for this page, /hmrc-internal-manuals/vat-records-manual/vatrec13020, returns 404; the working path is vat-trader-records.
3. Michael Brown, "Supplier Statement Reconciliation", Double Entry Bookkeeping
https://www.double-entry-bookkeeping.com/accounts-payable/supplier-statement-reconciliation/, last updated 17 December 2019.
A chartered accountant's worked example of reconciling a supplier statement to the purchase ledger, with the arithmetic shown. It supplies two things. The order of work in step 2 comes straight from it: agree opening balances, mark matching items, allocate credit notes and payments against invoices, then identify the remaining differences. Agreeing the opening balance first is the step small businesses skip, and skipping it means every difference found later might be an old one already dealt with. The second contribution is the distinction used in step 6, between a timing difference and an item that is simply "not due to timing, and will not correct itself in a later accounting period". The skill goes further than the source here. The source explains the difference conceptually; it does not give a test an owner can apply. This skill sets one: missing from two consecutive statements means it is an omission, and with only one statement in hand the row is marked UNCONFIRMED rather than chased. Chasing a supplier for a credit that was going to appear on next month's statement anyway costs goodwill for nothing, and goodwill with a food supplier is worth real money at the next price review.
4. Tipalti, "What is a 3-Way Match? How It Works in the AP Process"
https://tipalti.com/resources/learn/3-way-match/, last updated 28 July 2026.
A vendor explainer on the standard accounts payable control, defined on the page as "the process of comparing the purchase order, invoice, and goods receipt to make sure they match, prior to approving the invoice." Its list of compared fields — vendor and supplier name, total purchase amount, quantity of items, PO number, line items and product descriptions — became the columns of the transaction table in step 3, with delivery note number added because in hospitality the delivery note is the goods receipt and is usually the only evidence that exists. The skill deliberately departs from the source on tolerances. Tipalti recommends automatic tolerance thresholds, "like invoices within 3% of PO amount or variances under $100", so small differences pass without review. That is sound advice for a company processing thousands of invoices and bad advice for a fifty-cover restaurant, where a 3% tolerance on every delivery is the margin. The skill therefore sets no payment tolerance at all. It sets a listing floor instead: chase £5 and above individually, pool the rest, and escalate the pool to the owner once it passes £50, because a run of £2 shortfalls is a supplier problem and not a rounding problem.
5. JJ Tan / Jelly, "Supplier Credit Notes for UK Restaurants: Full Guide"
https://blog.getjelly.co.uk/supplier-credit-notes-restaurant/, published 25 August 2026, updated 4 September 2026.
The only source found that is written specifically for UK hospitality operators rather than for corporate accounts payable teams, which is why it is here. Its useful contribution is the receiving practice that creates the evidence this whole skill depends on: "Staff photograph the issue, note it on the invoice, and obtain the driver's co-signature on the spot rather than relying on later documentation." That is step 4's harvest list in one sentence, and it explains why the skill treats a photograph and a driver's signature as first-class evidence alongside the paperwork.
Two disagreements, and they are the reason to read this entry. First, the page states that "a supplier must issue a credit note within 14 days of the event that triggers the reduction in consideration, for example the date goods are returned, a pricing error is agreed, or a short delivery is confirmed." HMRC's own guidance at source 1 above says the fourteen days starts once the refund has been made to the customer, which is a different and usually much later moment. The skill follows HMRC and warns against quoting the deadline early. Second, the page carries a striking figure: "Unclaimed supplier credits in SME hospitality businesses typically represent 4–9% of spend, as operators claim only 3% on average against an entitlement of 7–12%." No study, survey or sample is cited anywhere on the page for it, and the page header credits the author as "AI SEO Agent" alongside the founder byline. The number is therefore not used anywhere in the skill and should not be repeated. It is recorded here only so that anyone who finds it elsewhere knows it traces back to an uncited claim on a marketing blog, not to research.
Best public prompt we found for this job
The closest public artefact is the reconciliation skill in Anthropic's own knowledge-work-plugins repository, at https://github.com/anthropics/knowledge-work-plugins/blob/main/finance/skills/reconciliation/SKILL.md, read on 13 September 2026 via raw.githubusercontent.com. Its star count is unread: api.github.com returned "API rate limit exceeded" from this machine and no authenticated GitHub client was available, so no figure is given rather than a guessed one. It is a general ledger-to-subledger and bank reconciliation skill, not a credit chase, and its escalation thresholds are in dollars and start at $10,000, so most of it is the wrong size for a pub. One line is worth copying exactly:
"This skill assists with reconciliation workflows but does not provide financial advice. All reconciliations should be reviewed by qualified financial professionals before sign-off."
That line is the one to take because it puts the limit at the end of the work rather than at the start. It does not refuse to do the reconciliation, and it does not hedge every figure inside it. It produces the finished schedule and then says plainly who has to sign it. For a credit chase that touches VAT on every row, that is exactly the right boundary: the owner gets a document good enough to send to the supplier, and the accountant is the one who posts it.
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