Friday night, 11.20pm. The fryers are off, the last scraps have gone, and someone is hunched over the counter counting a damp pile of tenners while the card machine prints its end-of-day roll. It is the least popular ten minutes of the week, and the one most likely to go wrong.

Nothing about this is exotic. The mistakes that cost chip shops money are small, repetitive and dull: a float that never gets counted, a tenner taken for staff lunch, a card total that does not quite match the till. On their own they are pennies. Over a year, they blur the line between a busy shop and a profitable one, and they make your accountant's job far harder than it needs to be.

The float nobody counts

Most shops open with a set float — say £150 in mixed change — and most shops cannot tell you what that float was last Tuesday. It gets topped up from the till when the fivers run out, and nobody writes down how much went in. By Friday, you are reconciling against a number that exists only in someone's memory.

Fix it by making the float a fixed, written figure. Count it back to that number before you cash up, every single day. If the float did go up midweek because you raided the drawer for change, record it as a transfer, not as an unexplained shortage. A float that drifts by £20 here and £30 there looks exactly like theft, and you will waste an evening accusing the wrong person.

Petty cash with no paper trail

Bread, milk, a bag of ice, the window cleaner, a tin of peas from the cash and carry. None of it is dishonest, and all of it breaks your records. Cash leaves the till with no docket, and at close you are short by an amount nobody can explain.

Keep a petty cash tin that is physically separate from the till drawer, with its own small float and a book beside it. Every withdrawal gets a line: date, amount, what for, who took it, and a receipt where one exists. Once a week, top the tin back up from the till and record that top-up. Two minutes of writing saves an hour of guesswork later.

The same rule applies to anything else that crosses the till drawer — staff wages, tips, the owner's pocket, cash for the window cleaner. If money moves, it goes on the sheet. No exceptions, including for yourself.

Card totals and till totals treated as one number

These are two different totals from two different systems, and treating them as one is where most reconciliation goes wrong. The till's end-of-day report tells you what was rung in. The card terminal's batch total tells you what was actually taken on cards. They should agree on card sales, allowing for timing.

They usually do not, for dull reasons:

• A card transaction taken at 11.55pm that settles on the terminal the following day.
• A refund processed on the card machine but never rung through the till.
• Tips added on the card reader that never appear as a till line.
• Two card machines, or a phone app payment, with only one being read at close.
• A failed payment retried, so the customer paid once but the till shows two attempts.

Write both totals on the close sheet, side by side, and add a line for the difference. Then look at that difference within 48 hours, while whoever was on shift still remembers the evening. A difference you investigate the next morning is a puzzle. A difference you find three weeks later is just a number.

Too many hands in the till

On a busy Saturday, three people use the same drawer: the counter, whoever covers the break, and the owner popping in after the match. Nobody knows who took what, and every unexplained shortage gets shared out fairly, which means it never gets solved.

Give each shift one person responsible for the drawer, with their own operator login on the till if the system supports it. On long shifts, do a mid-shift drop: count the bulk of the notes, seal them in a bag with the time and amount written on it, and put it somewhere secure. Record the drop on the sheet. If the counter and the fryer are swapping roles constantly, a second small drawer for the second till position is cheaper than the losses.

Discounts, comps and mates' rates

Family get free chips. The pub next door gets a trade rate. The delivery driver gets a can. All fine — as long as it is rung through the till as a discount, not simply not rung through at all.

Keep a short written list of who qualifies for what, and put it somewhere staff can see. If the till has discount buttons, use them and name them clearly. If it does not, keep a notebook beside the counter and write the discount down with a reason. The point is not to police generosity. It is to stop generosity and a genuine shortfall from looking identical on paper.

Voids, refunds and open drawers

A voided order, a refunded portion of chips, a drawer opened to break a twenty for a customer who then walked out — each of these needs a trace. At minimum, record:

1. The time it happened.
2. What the order was.
3. Why it was voided or refunded.
4. Who authorised it.

Then watch your no-sale count. A drawer opened without a sale should be rare. If the till log shows it happening thirty or forty times a shift, something is wrong with the process, the layout, or the honesty — and you will never spot which without the record.

Banking in erratic lumps

Cash builds in the safe for a week, then goes to the bank in one lump. When the deposit does not match the week's close sheets, you have no idea which day caused it. Do small, frequent drops and bank on a regular day. Keep paying-in slips with the matching close sheets so the paper story and the bank story can be compared in one sitting. Keeping less cash on the premises overnight is also the simplest security measure available to you, and it costs nothing.

A ten-minute close that stops most of this

You do not need new software. You need the same short routine, done the same way, by the same person, every night.

1. Count the float back to the agreed figure first, before you touch the takings.
2. Count the takings, ideally with a second person present, and never alone after dark.
3. Write the till's end-of-day total and the card terminal's batch total on the sheet, as separate lines.
4. List every cash movement: drops, petty cash, refunds, wages, discounts.
5. Write the difference down, even when it is annoying — especially when it is annoying.
6. File the sheet with the paying-in slip, card batch slip and any receipts.

Reviewed weekly, small differences tell you far more than one big difference noticed at year end. And when your bookkeeper gets a clean sheet with the card total, the cash total and the float all visible, the bookkeeping gets quicker and cheaper — which is money back in the shop.

Every shop's setup is different, particularly around VAT, tips and how card tips should be treated, so check your own arrangements with an accountant who knows hospitality before you change how you record things.

Photo: Kamil Čičila / Pexels