How long have I got, and what will it cost if I miss it?

Most of the clocks on UK penalty letters do not start on the day the envelope lands. They start on the date printed on the document. That is usually the day the issuer produced it, which can be several days before you see it. Count from the arrival date and you have already lost part of the window — sometimes enough of it that the discount is gone before you have sat down with the letter.

Post is the obvious culprit. A first-class letter that left Swansea or Newcastle on a Thursday can arrive on Saturday or Monday. A second-class letter can take longer still. Bank holidays sit inside calendar-day windows and do not pause them. If you were away, the letter sat on the mat and the clock kept running.

The other common error is treating every scheme as if it used the same clock. A council Penalty Charge Notice usually gives 28 calendar days to pay, with a reduced amount inside 14 days — 21 days for many London postal and camera notices. A DVLA Late Licensing Penalty halves if you pay within 33 calendar days of the letter date. A Dart Charge PCN reduces for 14 days. An NHS enquiry letter and an NHS Penalty Charge Notice each have their own 28-day clock. TV Licensing reminder letters are not a fine and have no published discount window at all.

None of those windows is “about a fortnight”. They are specific, they are written on the paper, and they are easy to flatten into a single remembered number that belongs to a different letter.

A discount period is not a reward for being cooperative. It is how several of these schemes are priced. The full amount is the amount; a smaller figure is offered for a short time at the start. Miss that window and the full amount is what is due — not because anyone decided you were difficult, but because the cheaper figure expired.

It is also not a challenge deadline. Paying inside the discount window and challenging the letter are different actions. On a council PCN, a challenge made inside the discount period often preserves that discount if the challenge is later rejected — the wording on your own notice is what counts. On a DVLA Late Licensing Penalty the £40 figure is a reduced payment, not a separate appeal clock. GOV.UK does not publish a single universal challenge deadline for those letters; the date on your document is the one that governs.

Some letters have no discount at all. An Out of Court Settlement is already the alternative to prosecution; there is no further reduction for paying quickly. TV Licensing reminder letters are not a penalty, so there is nothing to discount. Clean Air Zone penalties are set city by city, and there is no single national reduced figure this site can print without inventing one.

Where this calculator cannot source a reduced amount, it will not invent one. The result will say the window is unpublished and point you at the date on your letter. That is a worse sentence to read than a confident number, and it is the honest one.

Every one of these letters has a next stage. The next stage is almost always more expensive than the one before, and it happens on a timetable rather than because a person decided to pursue you.

For a council or TfL PCN the usual path is: the notice, then (if unpaid) a charge certificate adding 50%, then an order for recovery, then enforcement. Formal representations sit on a parallel track after a Notice to Owner, and a rejection of those representations opens a further 28 days to an independent adjudicator. Those are different clocks from the payment clock, and missing one does not automatically close the other.

A Dart Charge PCN is £70, reduced to £35 within 14 days, and must be paid within 28 days of receiving it. If it is neither paid nor successfully challenged in that time, a Charge Certificate can raise it to £105 (50% on the £70). Representations to Dart Charge have a 28-day window; if they are rejected, there are 28 days to appeal to the Traffic Penalty Tribunal, and after a Notice of Rejection an unpaid case also escalates. London ULEZ and Congestion Charge PCNs follow the same civil pattern as parking PCNs: £180, reduced to £90 within 14 days, then £270 on a charge certificate if unpaid after 28 days.

A DVLA Late Licensing Penalty that is not paid is referred to a debt collection agency. An Out of Court Settlement that is not taken up can be followed by prosecution, with published court maximums of £1,000 or five times the tax (no SORN) and £2,500 or five times the tax (SORN in force). Those maximums are ceilings, not typical outcomes, and they are not a “discount missed” figure.

An unanswered NHS enquiry letter becomes a Penalty Charge Notice after 28 days. An unpaid PCN then attracts a surcharge of 50% of the penalty, capped at £50. TV Licensing letters can be followed by a visit and, if a licence was needed and was not held, by a prosecution under the Communications Act 2003. The reminder letters themselves still have no discount window.

This site stops at the point a penalty becomes a debt being enforced. The escalation page sets out where that line is for each letter.

• What happens if you don’t respondThe next stage for each letter type, and how long you have.

Missing the reduced-payment window does not end the matter, and it does not usually end your ability to respond. What you cannot recover is the cheaper figure itself. The full amount is now the amount, and the next stage — whatever your scheme’s next stage is — is what you are working against.

A late response is still a response. For a council PCN, formal representations after a Notice to Owner have their own 28-day window. For Dart Charge, representations have 28 days from the PCN date. For an NHS Penalty Charge Notice, the 28-day clock on that notice is separate from the enquiry letter that came before it. For a DVLA letter, write using the date printed on the document in front of you.

If the letter date you type is years ago, the calculator will say so. Later documents may already have been issued — a charge certificate, a debt letter, a court notice. Use the latest document you hold, not the first one you found in a drawer.

If the date you type is in the future, the usual explanation is a typing error, or that you entered a payment-due date you estimated rather than the printed date. Check the paper.

If the amount on the letter does not match the published figure for the scheme you selected, that is not treated as an error here. It can mean a different scheme, a different authority’s rates, or something worth checking before you pay.

• Is this penalty letter genuine?How to check, without touching any link in the message.
• Appeal letter builderA starting draft assembled from templates. You fill the placeholders yourself.

Every figure the calculator prints comes from a single data file. Each scheme carries the published amounts (or an empty pair, which means “do not invent a number”), the discount and full-amount windows in days, whether those days are calendar days or working days, what the clock starts from, the escalation steps, a source URL and the date that source was last checked.

Calendar days are counted on the civil date. Adding days uses UTC date arithmetic so a BST or GMT boundary cannot shift the result by a day. If a scheme used working days, weekends would be skipped; bank holidays are not skipped, because a complete UK bank-holiday list varies by nation and inventing one would be a guess. None of the schemes in the file currently uses a working-day window.

The last day of a window is treated as still inside it. A Late Licensing Penalty dated 1 January with a 33-day window has its last reduced-payment day on 3 February. On 4 February that window has passed.

Nothing you type is sent anywhere. There is no account, no cookie for the form, and no analytics event that carries the date or the amount. Close the tab and it is gone.

Do I count from the day the letter arrived?

No. The published windows run from the date printed on the letter, which is usually the day the issuer produced it. Using the arrival date gives you days you do not have. That distinction is the most common way to get this wrong.

Why will it not tell me the amount for my council PCN?

Because the amount is set by the issuing authority, and there is no single national figure. GOV.UK publishes the 14-day and 28-day windows, not a universal pound amount. The calculator will give you the dates and refuse to invent a London, Manchester or any other council total.

Is the last day of the window still valid?

Yes. If the reduced-payment date is today, today is still inside the window. The day after that date is when it has passed. The letter is still the authority if its own wording is stricter.

The amount on my letter is different from the usual figure. Is it a scam?

Not necessarily. It can be a different scheme, a different authority’s rates, or a later stage (a charge certificate adds 50% on several civil penalties). Treat a mismatch as a reason to check, not as proof either way. The genuine-letter page explains how to confirm a notice through the official service you found yourself.

Does challenging it cost me the discount?

Not usually, on a council PCN: a challenge made inside the discount period normally preserves that discount if it is later rejected — check the wording on your own notice. Other schemes differ. The calculator does not treat a challenge as payment, and it will not tell you which to do.

I missed the discount months ago. Is there any point using this?

Yes, to see what the next published stage is and whether a later window is still open. A letter date more than three years ago is flagged, because later documents may already exist. Use the latest document you hold.

Does this work if JavaScript is off?

The calculator itself needs JavaScript. The written explanation, the official sources and the review date are in the page either way, so the figures and the rules are still readable.