August is the month that flatters you. The garden is full, the iced drinks are flying, the tills are busy from ten in the morning, and the bank balance looks the healthiest it has since Christmas.

September is the month cafés actually run out of cash.

Not because anything goes wrong. Because three of your largest bills converge in the space of a fortnight, at exactly the point your takings start to slide. It is entirely predictable, which is the frustrating part. And it is early August, so you have about seven weeks to do something about it.

Three bills, one month

1. Rent, if you pay quarterly

29 September is Michaelmas, one of the four English quarter days (25 March, 24 June, 29 September, 25 December). A lot of commercial leases still collect rent quarterly in advance on those dates, which means a full three months of rent leaves your account on a single Tuesday.

If you are on monthly rent, this one skips you entirely, and that is worth remembering because it is also one of the fixes further down.

If you are on quarterly rent, look at your last statement. The payment you made on 24 June covered July, August and September, and it felt fine because trade was strong. The one landing on 29 September covers October, November and December, paid out of your quietest takings since spring.

2. VAT, from your best quarter of the year

Your VAT stagger decides the exact date, but for a lot of cafés the return that covers the summer falls due in early autumn. A quarter ending 31 August is due, filed and paid, by 7 October.

That quarter contains June, July and August. Your three strongest trading months. Which means the VAT bill is the biggest one you will see all year.

The good quarter creates the big bill. You did nothing wrong: you traded well, you collected VAT on every flat white and every eat-in sandwich, and now HMRC wants back the part that was never yours.

3. Staff, twice over

Summer labour unwinds in September and it costs money on the way out. Seasonal staff finish, which means final pays plus any accrued holiday paid off in a lump. Students go back. The rota shrinks, but not before you have settled up.

At the same time your permanent team took their own leave over the summer, so you have been paying wages for people who were not in the building. If you have not looked at how holiday pay accrues and lands over late summer, it is worth an hour, because holiday is the payroll line that behaves least like the others.

The net effect: your September payroll is often higher than August, not lower, even though you served fewer people.

And then takings taper

While all of that is arriving, the top line quietly slides.

The tourists go home. If you trade anywhere with visitors, the drop is sharp rather than gradual.
The outdoor seats empty. Twenty covers of garden seating in July is ten covers in late September and four in the rain.
The iced line dies. Iced lattes, cold brew, milkshakes, ice cream. All of it falls off a cliff in a fortnight.
School-run trade returns, which helps, but it spends less per head. A coffee and a pastry is not a family of four having lunch.
Days get shorter, so lights and heating start creeping back onto the meter.

Trade does not disappear. It just changes shape, which is why the autumn menu changeover matters more than most people give it credit for. But the shape it changes into brings less cash in per week than August did.

What the gap actually looks like

Here is a simplified single site café, illustrative numbers, quarterly rent, VAT quarter ending 31 August.

Cash movement	August	September
Takings banked	£56,000	£45,000
Payroll, PAYE, NI, pension	£18,500	£19,200
Suppliers	£14,500	£13,000
Rent	£0	£6,000
Overheads (utilities, rates, insurance, software)	£4,500	£4,600
Net cash movement	+£18,500	+£2,200

Takings down about 20 percent. Payroll slightly up because of final pays and accrued holiday. Rent appearing from nowhere because the June quarter day covered July and August.

August put £18,500 into the bank. September puts £2,200 in. That is a £16,300 swing, and nothing has gone wrong.

Then on 7 October the VAT for the June to August quarter goes out. On this size of business that is realistically somewhere around £18,000 net, depending on how much of your trade is standard rated and what you reclaim on purchases.

So the fortnight from 29 September to 7 October takes roughly £24,000 out of the account, on the back of a month that only generated £2,200.

If you banked August's surplus, you are fine. If you spent it on a new espresso machine in the last week of August because the numbers looked great, you are ringing HMRC about a Time to Pay arrangement in October.

What to do about it in August

All of this is fixable, and almost none of it is fixable in late September. Here is the order I would do it in.

Build or refresh the cash flow forecast now

Do this first, this week, while August's numbers are good and you are in a decent mood about the business. A rolling 13-week cash flow forecast built in the second week of August reaches into the second week of November, which means quarter day, the VAT payment and the whole post-summer dip all sit on one page in front of you.

You are not looking for a number. You are looking for the shape of the closing balance line, and specifically the week where it dips lowest. Once you can see it, you have seven weeks to walk around it instead of into it.

Ring the landlord about monthly rent

This is the single highest-value phone call available to you in August, and most operators never make it.

Plenty of landlords and managing agents will agree to switch a quarterly lease to monthly payments, particularly for a tenant with a clean payment record. Some ask for a higher deposit, some say no. But it costs a phone call, and the answer is far likelier to be yes if you ask in August as a planning matter than in late September as a hardship request.

Turning one £6,000 payment into three £2,000 payments does not change your rent. It changes whether you can pay it without flinching.

Put the VAT aside weekly, not at the quarter end

The VAT you collect is not turnover. It is money you are holding for HMRC that happens to pass through your till.

Open a separate savings account, and every week when you bank the takings, move the VAT element across. As a rough working method, take roughly one sixth of your standard rated gross takings and treat it as untouchable. It will not be exact, and it does not need to be. It needs to be close, and it needs to be somewhere you cannot spend it by accident.

Time supplier payments deliberately, not by drift

There is a difference between deciding to pay a supplier on day 30 instead of day 14, and simply not paying anyone until they chase you.

The first is cash management. The second is how a good account quietly becomes a pro forma account, and what happens when a supplier puts you on stop in October is considerably worse than the cash gap you were trying to bridge.

If you need breathing room, ring the supplier in August and ask. Most wholesalers have heard the seasonal conversation before and would far rather agree an arrangement than send a van and get turned away.

Know your September break-even

August hides a multitude of sins because volume covers everything. September does not, so you need to know the number.

Work out your weekly fixed costs, apportion the rent monthly even if you pay it quarterly, divide by your gross margin and turn it into daily covers. On the café above, weekly fixed costs of about £5,800 at a 68 percent gross margin means roughly £8,530 of turnover a week, or £1,220 a day. At an average spend of £8.50 that is around 143 covers a day just to stand still.

September at £10,400 a week is about 175 covers a day, so there is headroom, but it is thinner than it looks. If you have never done this properly, working out your break-even point in covers per day takes about twenty minutes. Knowing the number does not make a wet Tuesday busier. It stops it being a surprise, and tells you honestly whether to cut a shift or ride it out.

Bank the August surplus

The hardest one, because August is exactly when the tired equipment, the shabby seating and the thing you have been meaning to replace all feel affordable.

August's surplus is not profit you have earned. It is the float that pays September's rent quarter and October's VAT. Spend it in September and October if it is still there. Not before.

The bottom line

September does not creep up on anyone who has looked. Quarter day is 29 September, and it is 29 September every year. The VAT deadline is printed on your return. The seasonal staff finish dates are in your own rota. The trade dip happens at the same point every autumn.

The reason it hurts is that all of it gets decided in August, when the café is busy and full and nobody wants to sit down with a spreadsheet.

Sit down with the spreadsheet. Ninety minutes this week, one phone call to the landlord, one new savings account for the VAT. Then go and enjoy the rest of August knowing that the last week of September is already handled.

Ed O'Brien has run Hunters Cake Company for 17 years across cafés in Witney, Burford, and a bakery in Carterton, Oxfordshire. He's building Brikly - modular tools that give independent café owners the same data the big chains have, without the big chain price tag.

The September squeeze: the rent quarter, the VAT bill and the post-summer dip