EPOS System: Receipts as Records

EPOS is the British and Irish word for the whole till, not for the box on the counter. That is not a vocabulary note. It puts a document inside the quote: the receipt, which in the UK and Ireland is a tax record before it is a receipt — and the paper it is printed on has to survive longer than the sale does.

The two acronyms name the same machine. A 15.6-inch terminal, an 80 mm printer, a steel drawer and a scanner are the same parts whether the catalogue heading says EPOS or POS. What differs is what the buyer expects the word to include, and the difference shows up in the one artifact the customer leaves with. A UK buyer asking for “an EPOS system” is usually asking for hardware, software, card processing and a support term as one package. A US buyer asking for “a POS system” is often asking about software alone. Neither notices the gap until the invoice is compared.

So this page takes the receipt seriously and works back from it. Two sizes of VAT document, the fields each one has to carry, six years of retention against a paper that fades, forty-eight characters against thirty-two, three VAT rates on one sale, and the five-cent rounding line that only Ireland needs. Every one of those is a hardware constraint disguised as paperwork: it decides the paper width, whether the drawer opens, whether the customer can check the arithmetic, and whether the copy filed at the end of the day is still legible when somebody asks for it.

We build the hardware in that sentence: all-in-one terminals from 11 to 15.6 inches, 80 and 58 mm receipt printers, cash drawers in three widths, 2D scanners, pole and VFD displays, and fanless mini PCs. We do not sell the till software, the card contract or the accountancy, and this page is careful about where the line falls — the tax rules are quoted from the regulations, and your accountant still decides how they apply to you.

The word·Two documents·Fields the till holds·Six years·48 vs 32 characters·Three rates·Five cent·Five documents·The counter·Four builds·When it is wrong·What we sell

What the word buys, and what it does not

Electronic point of sale. The adjective was doing real work in the 1980s, when the alternative was a mechanical register with a bell; every till sold today is electronic, so the “E” describes nothing. It survived because procurement documents, VAT guidance and job titles were written around it. A buyer who searches for one word and a supplier who only uses the other are invisible to each other, which is the commercial reason both words exist on this site. The definition itself, four layers and all, is on what an EPOS system is; this page is the hardware underneath it.

The scope is where they part. In British and Irish trade writing an EPOS system usually means the installed package: the terminal, the peripherals, the software licence, the card processing and a support contract, on one order. In North America the same phrase often means the application, with the hardware bought separately against a supported list. Both readings are legitimate, and a quote is where the difference turns into money.

The one hardware difference that is real

Very little changes at the machine. Three things do, and only one of them changes what the document can say.

The first is the mains lead. The UK uses the fused 13 A plug, so a terminal whose adapter is 110–240 V input still needs the right cord in the box; our 15.6-inch KSA is specified with a power cable “compatible with USA / EU / UK” and it is a line on the order, not a different machine. The second is the cash drawer’s note grips, which are covered in section nine because polymer notes changed the geometry. The third is the paper: UK and Irish tills default to 80 mm because that is the width at which a VAT invoice still reads as a table, and that is the argument the rest of this page is about.

What a UK quote has that the four layers do not explain

Hardware, operating system, application and payment link make up the machine. There is a fifth layer in the UK and Ireland that is not a layer at all: the record the machine produces. It is the one part of the system that outlives the terminal, is read by somebody who was not there, and has a retention period written into law. A till can be replaced in an afternoon; six years of invoices cannot.

Where EPOS and POS stop being interchangeable

Three phrases, three scopes, and the difference is what the buyer thinks they have bought.

Read the last column as the agenda for the first meeting. Every row is a scope mismatch that surfaces during installation otherwise.

The mPOS row is the one that catches shops out. A tablet with a card reader is a legitimate EPOS for a market stall — the hardware side of that is on tablet POS — and it is not a legitimate EPOS for a shop that has to hand a VAT invoice to a trade customer, because the document it produces is a payment confirmation rather than a tax invoice. The hardware is not the problem; the missing drawer port and the missing printer are.

A receipt is a VAT document, in one of two sizes

A VAT-registered retailer is not obliged to hand out a VAT invoice with every sale, but has to provide one when a taxable customer asks for it. That is the rule in the UK regulations, and it is what turns the receipt into a document with a field list. Below a threshold the field list is short; above it, the full invoice applies.

The threshold is £250 including VAT for the supply. Under it, a retailer’s invoice needs the supplier’s name, address and VAT registration number, the time of supply, a description of what was sold, the total including VAT, and — for each rate charged — the gross amount and the rate. Above it, the full particulars apply: an invoice number, the customer’s name and address, quantity and unit price excluding VAT per line, the VAT amount, and the net, VAT and gross totals.

The field list, side by side

Three documents get confused at a counter, and only the last two are VAT invoices. The middle column is what most UK shop receipts already are.

Drawn from the UK VAT Regulations 1995, regulations 16 and 16A, and the full particulars in regulations 13 and 14. The list is a floor, not a template; the rules change, and whether a particular sale falls either side of £250 is a question for your accountant.

Why the middle column is the one that matters

Most shop sales are under £250, so most receipts are simplified invoices — a document that needs the VAT number, the time of supply, a description, the total and the per-rate breakdown, and does not need the customer’s name. That is why a till that has never been asked for a trade invoice can still be non-compliant without anybody noticing: the fields it omits are the ones nobody asked for yet.

The three fields that are most often missing on an otherwise plausible receipt are the VAT number, the per-rate totals, and the time of supply in a form that survives a clock reset. Each of them is cheap to add and each of them is a software setting rather than a hardware capability — which is exactly why they get skipped when the hardware is ordered first.

What the second document costs on the counter

The full invoice is a table: quantity, unit price excluding VAT, rate, amount, and a subtotal per rate. A till roll has to hold five columns where an ordinary receipt holds two. That is a paper-width decision before it is a software one, and it is the subject of the fifth section.

It is also a decision that a shop makes once and lives with, because the same printer prints the queue ticket, the gift receipt and the trade invoice. A 58 mm printer can be perfect for two of those three and wrong for the one that has to be checked line by line by a customer holding a pen.

What the till has to hold, not just print

Printing a compliant receipt and being able to produce one later are different abilities, and a till can pass the first and fail the second. The first is a layout; the second is a database with the right fields in it and a number that never repeats.

Six things have to be written against each sale, not just rendered on the paper. If the software does not store them, no printer can recover them later.

None of this is a printer capability. It is the software’s contract with the hardware: the till has to be able to ask for the document again, years later.

The clock is a tax field

In a retail sale the time of supply is the date the goods are provided, and the receipt’s time stamp is that field. Which means the terminal’s real-time clock is not a convenience: a terminal that comes back from a power cut with a flat coin cell and boots to 1 January 1970 will print a day of invoices with the wrong tax point, and nothing about the paper will look wrong.

A till with no network time sync is a till whose invoices are only as accurate as its battery. Ask how the clock is set and what it does after a long power failure, and check the date on the first receipt after a weekend, not the first receipt after installation.

The queue is the other half of the clock

A till that keeps trading through an outage and syncs later is the right design. A till that stamps the sale at sync time is not: a two-hour outage at 23:30 moves that night’s turnover into the next day, and on the last day of a VAT period it moves it into the next return. The tax point has to be assigned on the terminal, at the moment of sale, and carried up with the transaction — the cloud copy is a queue, not the clock.

Reprint is not reissue

A second copy of a VAT invoice should be marked as a copy, because two identical documents with one number is an invitation to reclaim the same VAT twice. That is a software setting, and it is worth checking on a demonstration till rather than on the live one: print the same sale twice and see whether the paper says anything different the second time.

Six years is longer than the paper

A VAT-registered business has to keep its VAT records for at least six years from the date the record was issued, and ten if a One Stop Shop scheme is involved. HMRC’s own list of business records to keep puts bank statements, cash books, cheque stubs, paying-in slips and till rolls in the same sentence.

Now put a till roll in a shop window for a summer. Thermal paper does not carry ink; it carries a coating that darkens when the print head heats it, and the same reaction runs backwards in the presence of heat, light, friction and the plasticiser in a PVC wallet or a laminated pouch. A receipt that was perfectly legible on the day it was printed can be a grey rectangle by the time anybody wants to read it, and the failure is gradual enough that nobody notices which month it became unreadable.

What the hardware contributes anyway

Three things, and none of them is a durability claim on the paper.

The first is resolution. A 203 dpi head printing 576 dots across 72 mm gives a character cell of 12×24 dots, and the strokes inside that cell are what fade first: a thin character loses contrast before a thick one. The second is speed against darkness. At 220 mm/s the head spends less time over each dot than at 70 mm/s, so the setting that prints a darker mark is also the setting that prints slower — a till that has been tuned for queue speed is usually the one whose receipts fade first. The third is the top-coated roll: coating weight is a property of the paper you buy, and it is the only variable on this list that a shop can change after installation.

The practical file

Most shops end up with the same split, and it is worth stating because it changes what the printer is for. The document of record is a PDF exported by the software, filed by date; the till roll is the copy the customer leaves with and the shop keeps for the day. That is why a 58 mm roll can be entirely adequate for a bakery and entirely inadequate for a trade counter: the width is about the copy the customer has to read, not about the archive nobody prints.

The end-of-day report is the exception. A Z report is the shop’s own summary of the day — gross takings, split by rate, split by tender — and it is the one document that is normally printed and normally kept on paper. It is also the cross-check that makes a six-year-old invoice findable, because it carries the date, the invoice number range and the total.

48 characters is a table; 32 is a list

The arithmetic is not a matter of opinion. A 203 dpi head resolves 8 dots per millimetre. An 80 mm printer with a 72 mm print width carries 576 dots across the page; the standard font in that head is 12×24 dots, which is 1.5 mm wide and 3 mm tall. 576 divided by 12 is 48 characters, and 48 times 1.5 mm is exactly 72 mm — the print width, to the millimetre.

A 58 mm printer carries 384 dots and prints 48 mm, so the same font gives 32 characters. The paper is two-thirds the width and the line is two-thirds the length, and the characters are the same physical size on both, which is why the narrow roll is not a smaller version of the wide one; it is a shorter version of the same line.

There is a way to buy characters back. Font B in the 8370’s specification is 9×17 dots — 1.1 mm wide, 2.1 mm tall — which puts 64 characters across 72 mm. That is 64 columns at 1.1 mm per character, and it is a real option for an invoice table: the fields all fit, the numbers line up, and the customer needs better eyes or a brighter light. It is a trade, not a free upgrade. The mechanism behind those dot counts is on what a thermal printer is.

Where the columns go

A full VAT invoice needs five things on every line: description, quantity, unit price excluding VAT, rate, and amount. At 48 characters a description of 18 characters still leaves 30 for four numeric columns, and the header row can label them. At 32 characters the same line cannot be split five ways: the description takes one line and the numbers take the next, which is a list, not a table.

The cost is paper and patience. Take a twelve-line trade invoice. At 48 characters each line is one row: twelve rows, plus a header, plus five totals, plus a footer, twenty lines. At 32 characters each item is two rows, so the same invoice is thirty-two lines. At the 3.75 mm line spacing in the 8370’s specification that is 75 mm against 120 mm — both fit on a roll, and neither is the problem. The problem is that on the narrow roll there is no column of unit prices to add up, so the customer with a pen cannot check the invoice, and the invoice goes back to the office to be reissued on A4.

Dots per line from the 8360 and 8370 specification sheets; 203 dpi is 8 dots per millimetre, so 576 dots is 72 mm and 384 dots is 48 mm. Font B is listed on the 8370 sheet and not on the 8360 sheet, so the 64-column option is a printer-by-printer question rather than a paper one.

The width picks the drawer, not just the layout

There is a second, harder consequence. A cash drawer in this range opens on a 12 V or 24 V pulse delivered over an RJ11 or RJ12 port — the kick-out signal is worth reading before the order — and on a counter with an all-in-one terminal that port is on the printer. A 58 mm printer in the range is a USB and Bluetooth unit with no drawer port at all, which means the drawer has to be driven by the terminal instead — and a terminal without a drawer port cannot drive one.

So the choice between 80 and 58 mm is not only about how the invoice looks. On a counter with no separate drawer port, the narrow printer removes the drawer as well, and the shop discovers this when the drawer arrives and there is nowhere to plug it in.

Three printers, three answers

All three are thermal, all three speak ESC/POS, and they differ in the two things this section is about: what the line can hold, and whether the drawer has a port.

Three rates on one sale

A UK shop does not sell at one rate. Standard rate is 20 per cent, the reduced rate is 5 per cent, and zero-rated goods are 0 per cent, and a farm shop can hit all three in one basket: bread is zero-rated, a child’s car seat is reduced, olive oil is standard.

For a sale under £250 the simplified invoice needs the gross total at each rate and the rate itself. Over £250 the full invoice needs the net, the VAT and the gross, per rate. Either way the till has to keep the rate on the line and add up by rate at the end — a blended “VAT included” figure does not satisfy either document.

A basket over £250 has to produce the full document, which means three rate lines and a customer name and address. A till that can only print one VAT total cannot produce it, however good the printer is.

The reduced rate is not a discount. It has its own column, its own total, and its own line on the return, and a till that files a 5 per cent item under standard rate produces a document that looks right and a return that is wrong. On a small basket the difference is pennies; over a quarter it is the kind of error that gets found in an inspection rather than in a cash-up.

The penny, and why it is not nothing

VAT can be calculated per line and rounded, or calculated on the invoice total and rounded once. The two methods give different answers on a mixed basket, usually by a penny, and both are defensible as long as the till always does the same one and the accountant knows which. What is not defensible is a till that does one thing at the counter and another in the end-of-day report, because the two documents then disagree about the same sale.

A penny per sale is about £3 a day at 300 sales, and roughly £1,100 a year — not a rounding problem but an unexplained variance in the cash-up, which is where it will be treated as a staffing problem rather than a settings problem.

Ireland’s five cent, and the line it needs

Ireland rounds cash transactions to the nearest five cent. The convention is voluntary, applies only when the bill is paid in cash, applies to the total rather than to individual prices, and leaves card payments untouched. One and two cent coins remain legal tender, and a customer can insist on exact change.

The detail that matters for a till is in the tax treatment: VAT is charged on the unrounded amount, and the rounding is a separate line. A till that folds the rounding into the total produces a Z report whose cash figure cannot be reconciled, because the drawer holds the rounded amount and the report holds the unrounded one.

Rounding is on the bill total, after VAT, and only for cash. The four cases above are the whole rule: 1 and 2 down to zero, 3 and 4 up to five, 6 and 7 down to five, 8 and 9 up to ten.

What the till has to do that a UK till does not

Three settings, and each of them is a place where a till configured for the UK will quietly fail in Ireland.

The first is the rounding line itself: it has to print as its own line, after the gross and before the tender, so the customer can see the difference and the cashier can explain it. The second is the opt-out: a customer can ask for exact change, so the rounding must be selectable per transaction rather than a global switch. The third is the Z report, which needs a rounding total of its own — counted cash equals gross plus or minus rounding, and if that line is missing the day’s difference is small, which is worse than large, because a small difference at the end of the day is the one that gets blamed on the cashier.

The same question in the UK

There is no rounding convention for cash in the UK, so the rounding line is a column of zeros and the cash-up ties to the penny. That is worth knowing before a group buys one till configuration for shops on both sides of the Irish Sea: the difference is not cosmetic, and it lives in software rather than in the printer.

The five documents a day produces

A till is a document machine that happens to take money. Follow one day and the document list is short, and every item on it is a different requirement on the hardware.

The last row is the one that decides whether an EPOS system is a record system or only a printing system. It is also the one row no printer can fix.

One of the five is printed at every sale, one at close, two on request, and the opening float not at all. Only the Z report is reliably kept on paper, which is why the paper choice matters most for the two documents that leave the shop: the receipt the customer takes and the Z the accountant reads.

The Z is the index

An end-of-day report is not a total, it is an index. It carries the date, the invoice number range, the split by rate and the split by tender, which is what makes a six-year-old invoice findable at all: the customer has a date, the date has a range, the range has a number. A shop that keeps only the Z reports can still answer “what was sold on 14 March” without keeping every receipt.

That is why the Z has to be printed rather than only stored, and why the report and the receipts have to agree about the same penny. A Z that rounds differently from the till produces a report that cannot be reconciled with its own receipts, and the first person to notice is usually an inspector rather than the owner.

The refund is the document people get wrong

A credit note is not a negative receipt. It has to identify the invoice it cancels, say why it was issued, and state the amount credited excluding VAT. A till that can refund a sale but cannot print the original invoice number is a till that produces a document which cannot be tied to anything — and the shop’s own copy of the original is the only thing that can fix it later.

The drawer, the reader and the second screen

Three things sit around the terminal, and each of them is decided by a document requirement rather than by a specification sheet.

The drawer, and the £20 note

Polymer notes are smaller than the paper ones they replaced. A paper £20 was 149×80 mm; the polymer note is 139×73 mm. The ten millimetres that came off the length do not matter much, because notes lie with the long edge running back into the drawer; the seven millimetres that came off the short edge do, because that is the dimension a bill compartment has to hold.

A tray moulded to the width of a paper note is 80 mm at the slot. Put a 73 mm polymer note in it and the stack leans forward with nothing behind it, which is why the drawers in this range use metal wire grips rather than moulded slots: a spring clip presses whatever it is given. If a drawer is being specified for a UK shop, that is the question to ask, and it is a question about the tray rather than about the box — what a cash drawer is covers the rest of it.

The coin side is arithmetic. The UK has eight coins in circulation — 1p, 2p, 5p, 10p, 20p, 50p, £1, £2 — and a tray with eight adjustable coin slots fits them exactly. Ireland also runs eight — 1c, 2c, 5c, 10c, 20c, 50c, €1, €2 — so the same tray works on both sides of the Irish Sea, which is worth knowing before a group buys two drawer variants.

All three are steel, all three have a three-position lock, and all three specify the solenoid voltage at order — 12 V or 24 V — because it has to match the port it is plugged into. A 24 V drawer on a 12 V port does not open; a 12 V drawer on a 24 V port opens once.

The reader, and the back of a driving licence

Age-restricted sales are the reason a 1D laser is no longer enough at a UK counter. A photocard driving licence carries a PDF417 two-dimensional code on the back, and a passport, a residence permit and a proof-of-age card carry their own. A 1D scanner reads the barcode on a bottle and nothing else; a 2D imager reads the licence, the QR code on a phone screen for a loyalty app, and the GS1-128 on a delivery carton.

That is a document argument as well: an age-verified sale is one a shop may have to defend later, and the till records the scan rather than the cashier’s judgement. It is the same category of evidence as the invoice.

The desktop unit is for items pushed across the glass; the handheld is for a counter with no free surface; the wireless omni carries a 100,000-code cache, which is what makes an aisle count possible without a network.

The second screen, and the video output problem

A 2×20 vacuum fluorescent display holds forty characters on two lines. That is enough for a running total and a tender, and it is not enough for a VAT breakdown: three rate bands plus a gross plus a rounding line is six numbers, and a customer who is checking an invoice needs to see them together.

A 10-inch LCD can show them, and it can show the shop’s own content between sales. What it cannot do is connect itself. A pole display takes HDMI or VGA, and most Android terminals in this range do not have a video output at all — the 15.6-inch 155A publishes a 12 V input and an RS-232 port and nothing else, so a pole screen has to be driven by something that does have one: the KSA with its HDMI option, the Windows 152W with VGA and HDMI, or a mini PC. A VFD, by contrast, runs on USB and works with everything.

Forty characters for a running total, or 1280×800 for a breakdown the customer can read — the choice is between a screen that works with any till and a screen that needs a video cable.

Four counters, and the port that picks them

The four builds below are not price tiers. They are four answers to one question: where does the drawer pulse come from, and what does the rest of the bill look like? That single port decides the terminal, the printer and the paper width together, and getting it wrong is the failure that shows up on the first day rather than in the first month.

Voltages are from the printer specification sheets; the drawer is ordered at the voltage of the port it will use. A drawer ordered at 24 V for a 12 V port is the most common ordering error on this page, and it is invisible until the first sale.

Six terminals, one column each

Every one of these has been chosen for what leaves the body: a printer, a drawer port, a video output, or nothing at all.

The two-part check

Before an order, two sentences settle most of it. First: which port opens the drawer, and what voltage does it supply? Second: what is the widest document this till has to print, and does it fit in 48 characters? A counter plan that answers both has already chosen the terminal, the printer, the paper and the drawer.

The third sentence is the one people forget: who prints the invoice the customer keeps? If it is the till, the paper width is a customer-facing decision. If it is the software on A4, the till roll is only the shop’s working copy, and 58 mm may be entirely reasonable.

Where an EPOS system is the wrong purchase

Four situations, and in each of them the hardware is fine and the expectation is not.

• A shop that takes no cash. A drawer, a lock and a cash-up procedure are dead weight in a card-only business, and the steel box becomes a security liability rather than an asset. Keep the terminal, the printer and the software; take the drawer off the quote.
• A business that needs A4 invoices with a logo. A till roll is a working document, not a letterhead. If the invoice is going to a customer’s accounts department by email, the software produces it and the till prints the slip that goes in the bag.
• A shop that is not VAT-registered. Half of this page stops applying: there is no VAT number to print, no per-rate split, and no six-year VAT record. A simpler till and a 58 mm printer is a reasonable answer, and selling the wide one on document grounds would be overselling.
• A site that expects stock control from the till. An EPOS system records what was sold, not what is on a shelf. The two are related by a stock file somebody has to maintain, and a shop that buys a till expecting the shelf count to fix itself will end up exporting a CSV and doing it in a spreadsheet anyway.

There is a fifth, softer one. A shop with one counter, fewer than thirty sales a day and no trade customers does not need a document system; it needs a till that does not fail. The invoice argument on this page is real, and it is proportional to how often somebody asks for a proper invoice.

What we sell, and the three questions we cannot answer

We build hardware. That is the line, and it is worth being exact about it because an EPOS system is a package in the UK sense and no hardware supplier can deliver the whole of it.

What we make: all-in-one terminals from 11 to 15.6 inches in Android and Windows, 80 and 58 mm receipt printers, cash drawers in three widths, 2D scanners in desktop, handheld and wireless forms, pole and VFD customer displays, and fanless mini PCs. What we do not: the till software, the card acquiring contract, the installation labour, or the tax advice.

The three questions to put to the software vendor

They are all about the document, and none of them is on a feature list.

• Show me an invoice from two years ago, and print a copy. Not a report of what was sold — the document itself, with the same number and the same tax point, marked as a copy.
• Put three rates on one sale and show me the totals by rate. If the answer is a single VAT line, the software cannot produce a full invoice on a mixed basket.
• Set the rounding line and show me the Z report. In Ireland this is a requirement; in the UK it is a good test of whether the software has ever been configured for a market other than its home one.

Three pages go deeper on parts of this one: a POS system by counter position, what a system costs and which lines are whose, and the tablet version of the same argument. The sector pages take the same hardware into a shop: grocery, cafe, salon, small business, cloud. On the printer itself there are 80 mm against 58 mm and why receipt printers fail, and the questions we get asked most are on the FAQ.

FAQ