Tax year 2026/27, checked against HMRC guidance August 2026. Add the lot to your phone in one tap, then forget about it — that's the point.
Add every deadline to my phone calendarWorks with iPhone and Android calendars. Each date comes with a 3-day warning built in.
| Date | What | Who it hits |
|---|---|---|
| 19th | CIS contractor return (CIS300) for the month to the 5th | Anyone who pays subbies — miss it and it's £100, automatically |
| 22nd | PAYE & CIS deductions paid to HMRC (electronic) | Employers and contractors |
| Deadline | Covers |
|---|---|
| 7 August 2026 | 6 April – 5 July (already gone — if you missed it, see below) |
| 7 November 2026 | 6 April – 5 October |
| 7 February 2027 | 6 April – 5 January |
| 7 May 2027 | 6 April – 5 April (the full year) |
Straight answer on penalties: HMRC aren't issuing penalty points on late quarterly updates in year one. That grace ends with 2026/27, it doesn't cover the final declaration, and you can't file the final declaration until all four quarters are in. Behind already? Start here — no lecture.
| Date | What |
|---|---|
| 5 October 2026 | Register for Self Assessment if you went self-employed in 2025/26 |
| 31 October 2026 | Paper tax return deadline (file digitally and ignore this one) |
| 31 January 2027 | 2025/26 tax return + balancing payment + first payment on account. The January that hurts — unless you've set aside monthly |
| 31 July 2027 | Second payment on account for 2026/27 |
Your VAT return and payment are due 1 month and 7 days after your quarter ends — but quarter dates vary by business (your "stagger"). Check yours in your VAT account, or ring us and we'll tell you in thirty seconds. On CIS work between VAT-registered businesses, remember the reverse charge changes what goes on the invoice — the calculator handles it.
Every one of these deadlines is included in every CIS Books plan — filed on time, with a text to say it's done. That's the whole product. From £69/month.