Transfers (Jacoby Tansfers) are used after partner has opened 1NT, or 2NT. If you hold a five+-card suit, bid the suit that's ranked immediately below the suit you actually have (i.e. if you hold hearts, bid diamonds and if you hold spades, bid hearts). This asks partner to bid your suit (regardless of how they like it). This gives you another round of the bidding to describe your hand more accurately. Transfers can be any point count from 0-anything.
Stayman and Transfers go together. Stayman is usually for four suits, and transfers for five or longer suits. 1NT is opened by partner, pass to you…
• 2♣ is Stayman
• 2♦ (transfer) asks opener to bid 2♥
• 2♥ (transfer) asks opener to bid 2♠
• 2♠ (transfer) asked opener to bid 3♣
• 2NT (transfer) asks opener to bid 3♦
NB: If 2NT is used as a transfer to diamonds, you lose the natural 8,9 point raise to 2NT. You can manage this by bidding 2♣ (which is, ostensibly, Stayman), and then bid 2NT over whatever partner answers.1NT p 2♣ p 2♦ p 2NT shows an invitational balanced hand with 8,9 points, not necessarily with a major.
Opener’s Next Move
In response to a transfer bid of 2♦, 2♥, 2♠ or 2NT, opener bids the requested suit at the next level 1NT p (2♦ transfer to hearts) p 2♥ (bidding what partner has asked you to) so that you will play the hand. On rare occasions, you might superaccept by jumping to the three level in the requested suit (if a major) with four card support and (usually) maximum points, e.g. 1NT p 2♦ P 3♥. This tells partner you really like their suit. This follows the Law of Total Tricks (nine trumps = bid at the three level.)
Responder’s Rebid after a Transfer
• Pass, with 0-7 points, to play in a major partscore: 1NT p 2♦ p 2♥ p p p
• 2NT is invitational (8,9 pts), showing five cards in the major: 1NT p 2♦ p 2♥ p 2NT
• 3♥ or 3♠ is invitational, showing a six+ cards: 1NT p 2♦ p 2♥ p 3♥
• 4♥ or 4♠ is 10+ points with six cards: 1NT p 2♦ p 2♥ p 4♥
• 3NT shows five cards in the major, and asks opener to choose 3NT (with two cards in the major) or 4 of the major (with three+ cards):1NT p 2♦ p 2♥ p 3NT/4♥
• A new suit bid is natural and game forcing: 1NT p 2♦ p 2♥ p 3♣
If the opening 1NT bid is doubled:
• System is on (ie all bids retain their normal meaning) 2♣ is still Stayman, and transfers apply
If there is an Overcall rather than Double,
• Transfers no longer apply, system is off, and
• All responder’s bids are natural, except if the overcall is 2♣, then “Double” is Stayman
If there is interference after the transfer bid: eg 1NT p 2♦ (3♣), opener can pass with minimum and a doubleton in the suit. To accept the transfer shows 3+ cards.
• Transfers are also used in the Majors over a 2NT opening (20-21), or 2♣ followed by 2NT (22-24). 2NT p 3♦ is a transfer to hearts, as is 2♣ p 2♦ p 2NT p 3♦.