Club 100 is a monthly lottery run by Colgrain Primary Parent Council to raise money for Colgrain Primary School in Helensburgh. It is a small society lottery registered with Argyll & Bute Council. The member responsible for it is Ryan Garrett (Chair), c/o Colgrain Primary School, Red Gauntlet Road, Helensburgh G84 7TZ. You must be 18 or over to play.

£5 per entry, per month, paid automatically by Direct Debit. You can have up to 10 entries — each one is a separate chance to win and has its own number. It's one membership per email address; to add entries later, email club100@colgrainparentcouncil.co.uk.

Each entry has its own number from 1 to 300. When you join you can pick any number that's free — a birthday, a door number, whatever you like — or leave it blank and we'll choose a free one at random. No two people ever share a number.

Your numbers are held for you while you finish setting up your Direct Debit, and they stay yours every month for as long as you're a member. You can swap a number for any free one online, except from the 1st of each month until the draw for the month just ended has run (normally on the 12th, and after the 16th at the latest).

Three winners are drawn every month, and the prizes come from the money actually paid for that month:

• 1st prize: 25%
• 2nd prize: 15%
• 3rd prize: 10%

That's half paid back out in prizes. Of the rest, about 6% covers the cost of collecting the money (30p on a £5 entry), so around 44% goes to the school via the Parent Council — funding trips, equipment and activities for the children. The law asks for at least 20%. The three winners are always three different people; if fewer than three people are in a draw, fewer prizes are given and the rest stays with the school.

No — never. On our Winners page, and anywhere else the Parent Council mentions Club 100, we only ever show the winning number, the place and the prize — for example “Number 42 — 1st place — £18.75”. If your number comes up, we email you privately.

Each month is drawn on the 12th of the following month at 09:00 UTC (9am in winter, 10am in summer) — so October is drawn on 12 November, once all of October's payments have cleared. If the draw can't run on the 12th it is tried again each day up to the 16th.

There's no live event. At the moment of the draw, the computer makes a random “seed” using a cryptographic random number generator, then picks the winners from the list of every number in the draw using a published method in which every ticket has exactly the same chance. The seed and the full list are recorded permanently and shown on the draw page — so the draw is recorded and reproducible: anyone can re-run it and get the same winners. (The seed is not announced beforehand; it is made at the moment of the draw.)

Setting up a Direct Debit usually takes about 3 working days. Your first payment counts for the month you joined, so once it has cleared you're in that month's draw, held on the 12th of the following month, even if you join on the last day of the month and the payment is taken a few days into the next one (as long as it is requested by the 6th of that next month, as it normally is). If you join near the end of a month, your first two payments may be close together: one for the month you joined and, about a week later, one for the next month. Your welcome email says which draw to expect.

When card payment is offered, you can pay once by card for a one-off entry in one draw: the draw for the month you pay in, held on the 12th of the next month (for example, paying on 3 November enters the November draw on 12 December). The join page and your confirmation email name the exact draw and date. Nothing more is ever taken, and a card entry's numbers go back into the pool after that draw — so it doesn't keep the same number every month.

By bank transfer from the Parent Council's account. Your winner email has a single-use secure link where you give the UK bank account to pay into; we usually pay within a week of getting your details. We will never ask for bank details by phone, text or social media.

You have 90 days from the draw to send your details. If a link has expired, just reply to the email and we'll send a fresh one. A prize that isn't claimed within 90 days passes to the school.

Both from Manage my membership — pop in your email address and we'll send you a link (it lasts 45 minutes). You can cancel at any time with no penalty. Prefer to ask a person? Email club100@colgrainparentcouncil.co.uk.

When you cancel, no new payments are requested. A payment that has already gone to your bank can't be stopped, so it will still be taken — and you're in the draw it paid for. You stay in the draw for every month you've paid for. Your number goes back into the pool on the 13th of the month after you cancel, and never before every month you paid for has been drawn. If no payment was ever taken or requested from you, it goes back straight away.

You can swap your number for any free one as often as you like, except from the 1st of each month until the draw for the month just ended has run (normally on the 12th, and after the 16th at the latest), when numbers stay put.

Yes, if you're a Direct Debit member: go to Leave a review and we'll email you a link to your membership page, where you can give a star rating and a short comment (and change or withdraw it later). Every review is read by a Parent Council officer before it appears, and we publish good and bad alike — see what members say and our reviews policy.

Free, confidential support is available 24/7 from the National Gambling Helpline on 0808 8020 133 and at BeGambleAware.org. You can cancel your membership at any time.

In our Rules & Terms and Privacy Notice.