How to select prize draw winners fairly
To select a prize draw winner fairly, fix the complete list of valid entries before the draw, give every entry the same chance, including free entries, choose the winner with a random method nobody can influence or repeat, and keep evidence of what was drawn, from which list and when. In the UK, the main rules are the CAP Code, which the Advertising Standards Authority (ASA) applies to prize promotions advertised in the UK, and the Department for Culture, Media and Sport’s Voluntary Code of Good Practice for Prize Draw Operators.
The rules that apply in the UK
- The CAP Code (Section 8, promotional marketing). Written by the Committee of Advertising Practice and enforced by the ASA, it applies to prize promotions advertised in the UK. Prizes must be awarded according to the laws of chance, and the ASA expects promoters to have evidence that a winner was selected randomly.
- The DCMS Voluntary Code of Good Practice for Prize Draw Operators. Published in November 2025 and in effect from 20 May 2026 for operators who sign up to it. It covers how winners are selected, transparency and player protection.
- The Gambling Act 2005. It decides whether a paid-entry draw is a lawful prize draw or an unlicensed lottery, which is why free entry routes matter.
1. Build a complete, clean entry list
Close entries at the time your terms say, then remove anything your rules exclude, such as late entries or entries over a stated limit. Do this before the draw, not after you’ve seen who won. Decide in your rules whether each person gets one entry or one per ticket, and apply that rule to the list. Keep a copy of the final list exactly as it was drawn from.
2. Include free entries on equal terms
Under the Gambling Act 2005, a prize draw that people pay to enter generally needs a free entry route unless it’s a genuine skill competition. Free entries must go into the same draw as paid entries, with the same chance of winning. The DCMS Code also says arrangements must allow enough time for free entries, such as postal entries, to be validly received before the draw.
3. Choose a selection method
Under the CAP Code, winners must be chosen according to the laws of chance. If you use a computer, it should be a verifiably random process, and the ASA expects to see evidence of it. If you don’t, rule 8.24 requires winners to be selected by, or under the supervision of, a demonstrably independent observer. The ASA has upheld complaints where a member of staff picked winners by hand, because staff aren’t independent.
The DCMS Code describes three accepted ways to select winners:
- by an independent person, or under their supervision
- by a computer process that produces “verifiably random and auditable results”
- by a physical draw machine
Picking a name by hand from a list, or re-running a spreadsheet formula, leaves you nothing to show afterwards. A dedicated draw tool like WinnerSelect’s random winner picker selects the winner on a server and keeps the record for you.
4. Fix the list before the draw
The strongest evidence of a fair draw is proof that the list didn’t change. Good draw software locks the entry list and records a fingerprint of it: a short code calculated from every entry, which changes completely if a single entry is added, removed or altered. Anyone holding a copy of the list can later check it against the fingerprint.
5. Draw once, and decide re-draws in advance
Run the draw once. Re-drawing until you get a result you prefer is the most common way draws go wrong, and with most free tools nobody would ever know. If you need several winners, draw them together in one draw, in order. If you want back-up winners in case a winner can’t be contacted, say so in your rules and draw them in the same draw.
6. Keep evidence of every draw
The ASA expects promoters to be able to show that a winner was selected randomly, and a record is how you do it. For every draw, record:
- the date and time it ran
- who ran it and the method used
- the number of entries
- the fingerprint of the entry list
- the winners, in the order drawn
Keep winner records for as long as you might need to answer questions about the promotion. Neither code sets a retention period for entry lists. Under UK GDPR you shouldn’t keep personal data longer than you need, so many operators delete entry lists after a fixed period and keep the winning entries.
7. Tell entrants how winners are notified and announced
Your terms should say how and when winners will be notified (CAP Code rule 8.28.4). Under rule 8.28.5, you must publish or make available information showing a valid award took place, which ordinarily means the surname and county of major prizewinners. Tell entrants this at or before entry and give them the chance to object to, or limit, what’s published; you must still be able to give the details to the ASA if challenged. The DCMS Code also asks operators to give a clear summary of each draw’s rules and mechanism and to say that prizes are awarded by chance.
What “random” should mean
There’s no legal standard for randomness in prize draws. The closest UK benchmark is the Gambling Commission’s technical standard for generating random outcomes (RTS 7), written for licensed gambling rather than prize draws. In plain terms, it expects outcomes that are evenly distributed, unpredictable, not seeded in a way that makes them predictable, and never swapped for a different result after the fact. Spreadsheet functions and simple scripts aren’t built with those properties in mind; generators designed for cryptography are.
How WinnerSelect does it
WinnerSelect picks winners on its own servers using a cryptographically secure random number generator, with a selection method that gives every entry exactly the same chance. It is designed to meet the technical requirements of RTS 7. The entry list is locked and fingerprinted before any winner is chosen, all winners are drawn in one step with no re-rolls, test draws are marked as tests everywhere, and every draw is kept as a permanent record. See Draw standards, or try the random winner picker. For agencies running draws for clients, see Prize draw software for agencies.
Checklist
Before the draw:
- Entries closed at the time in your terms
- Invalid entries removed under your rules
- Free entries included on equal terms
- Number of winners and any back-up winners set in your rules
- Terms say how and when winners are notified, and what winner details will be published
During the draw:
- Entry list locked and fingerprinted
- Winners selected once, by a verifiably random method or under an independent observer
After the draw:
- Evidence kept: time, method, entry count, fingerprint, winners in order
- Winners contacted in line with your terms
- Winner details published or available on request
- Entry list kept or deleted in line with your retention policy
Frequently asked questions
Can I pick prize draw winners with a spreadsheet?
You can, but a spreadsheet recalculates every time it changes, isn’t designed for security-grade randomness, and leaves no fixed record of a single draw, which is the evidence the ASA expects to see if an entrant complains.
Do I need an independent person to oversee the draw?
Not if you use a verifiably random computer process and can evidence it. Under CAP Code rule 8.24, an independent observer is needed when winners aren’t selected that way, and a member of your own staff doesn’t count. The DCMS Code likewise accepts either an independent person or a computer process producing verifiably random and auditable results.
Do I have to publish the winner’s name?
Under CAP Code rule 8.28.5, you must publish or make available information showing a valid award took place, ordinarily the surname and county of major prizewinners. Tell entrants at or before entry, and let them object to or limit what’s published.
Can I re-draw if the winner doesn’t respond?
Only if your rules say so. Set out in your terms how long a winner has to respond, and draw any back-up winners in the same draw as the main winner.
How long should I keep prize draw records?
Neither the CAP Code nor the DCMS Code sets a period. Keep winner records long enough to answer questions about the promotion, and delete entrants’ personal data once you no longer need it, in line with UK GDPR.
Is a live-streamed draw automatically fair?
No. A live stream shows a draw happening, but not whether the list was complete or the method random. A fixed entry list and a permanent record matter more than the camera.
This guide is general information, not legal advice. For advice on a specific promotion, speak to a solicitor.