Transfers over 1♣ can seem a bit fancy, but they are actually straight forward, easy to learn and play.
How they work
After partner opens 1♣, this is what the bids mean
1♦ = 4+ hearts
1♥ = 4+ spades
1♠ = *Subject to partnership agreement. Recommendation - no 4 card major.
In other words, partner's "transfer" simply just shows that suit, it doesn't force us to accept the transfer. More on further down.
The 1♠ bid
This is a bid which is important to discuss with your partner if you are thinking of playing transfers over 1♣. Some people play 1♠ to mean diamonds, others play it to show no major. My preference is to just show no major
A side point: If you are going to play transfers over 1♣, ask yourself these two questions
1. How do I show a weak hand with a minor?
2. How do I show a game forcing hand with a minor?
My recommendations
With a weak hand and a minor, start with 1♠, then just bid the minor. Simple and effective, so for example
On this hand, we simply start by saying "no major", and then we bid the minor we want to play in.
In relation to the above rule, 90% of the time after 1♣ P 1♠, partner will rebid 1NT, but not always. Don't let transfers confuse you, you should still bid your hand! For example
In this hand for example, we simply rebid our hand normally. Partner's 1♠ does not force us to bid 1NT in any way, however any time we have a 12-14 balanced hand we should certainly be rebidding 1NT - in other words, we bid naturally.
After 1♣ P 1♥ or 1♣ P 1♦, do we always accept the transfer?
This is something to discuss with partner, I will give my recommendation but there are other ways people play it so it is worth discussing exactly with your partner, or if you come up against it, clarify with your opponents exactly what the bids mean if you need to.
Accepting the transfer shows exactly 3 cards in the suit. For example
In this example partner's 1♥ shows 4+ spades. It is not a strict transfer, however here we are happy to bid 1♠ to show exactly 3 cards. Lets contrast this with a couple other hands
Here we have not bid 1♠ since we only have 2, we have rebid 1NT, showing 12-14 balanced without 3 spades.
One other point - what do you do with 4 card support? Lets change the hand slightly
We bid 2♠ simply. This is the same as if, playing natural methods, the auction had gone 1♣ 1♠ 2♠. So, we are able to differentiate between 4 card, 3 card and 2 card support!
Important points
1. Checkback. Checkback is beyond the scope of this article, but ask partner when and how checkback applies. I will make recommendations for that in my article on the topic.
2. What happens in competition? My simple suggestion is, just play all natural bids in competition, it is the best way to avoid confusion in most partnerships - in other words "All system off in competition".
3. It is generally a good idea to discuss follow up auctions, and also always keep in mind that even though you are playing transfers, normal bidding principles still apply. Just treat the "transfer" as having shown the suit, for example
On that hand it is as if south has just bid spades twice, showing a weak hand with spades, don't let the fact that you are playing transfers confuse simple auctions like that.
Read next: Texas Transfers: Transfer Directly to Game · System Over 1NT: Transfer Responses and Conventions · Fourth Suit Forcing: How and When to Use It