Bid Increments
Three modes — fixed, variable, percentage. Configurable per-auction or globally.
Fixed
The simplest mode. Every bid must beat the current price by exactly this amount.
| Setting | Example |
|---|---|
| Increment | 10 |
| Bid behavior | Always +$10 over current |
| Current price | Min next bid |
|---|---|
| $0 (start) | start price |
| $100 | $110 |
| $250 | $260 |
Configure in Add Auction → Pricing → Increment type: Fixed → value.
Variable (tiered)
Increment changes based on the current bid level. Define a tier table.
Example tier table
| When current price < | Increment becomes |
|---|---|
| $100 | $5 |
| $500 | $25 |
| $1,000 | $50 |
| $5,000 | $100 |
| $10,000 | $250 |
| (any higher) | $500 |
| Current price | Min next bid |
|---|---|
| $50 | $55 |
| $200 | $225 |
| $750 | $800 |
| $4,500 | $4,600 |
| $8,000 | $8,250 |
| $50,000 | $50,500 |
How to configure
In the Add Auction form:
- Increment type → Variable
- Click Add tier to add a row
- Below price + Increment for each tier
- Tiers must be in ascending order (UI auto-sorts on save)
The tier table is stored as JSON in wkafw_auctions.variable_increments.
CSV import / export
For repeatable rules across many auctions:
| Tool | Action |
|---|---|
| Tools → CSV → Export increments | Downloads current tier table |
| Tools → CSV → Import increments | Bulk-set tier tables across auctions |
CSV format:
auction_id,below_price,increment
123,100,5
123,500,25
123,1000,50
Percentage
Increment is a percentage of the current price. Always rounded up to the nearest cent (or your currency's smallest unit).
| Setting | Example |
|---|---|
| Increment % | 5 |
| Bid behavior | Always at least +5% over current |
| Current price | Min next bid (5%) |
|---|---|
| $100 | $105.00 |
| $250 | $262.50 |
| $1,000 | $1,050.00 |
| $9,999 | $10,498.95 |
Use cases:
- Real estate / luxury auctions where stakes scale with price
- Currencies with very different denominations (e.g. JPY where +¥1 is meaningless)
Per-auction vs global
| Source | When used |
|---|---|
Per-auction bid_increment field | Always wins |
Global wkafw_bid_increment option | Default for new auctions in Add Auction form |
You can set a sensible global default and override per-auction for special cases.
Validation
When a bidder submits a bid:
- Engine reads the auction's
increment_type(fixed/variable/percentage) - Computes the required minimum increment for the current price
- If
bid_amount < current_price + increment, rejects with:"Bid must be at least $X"
The bid form shows the suggested minimum in the input placeholder for guidance.
Quick-bid buttons
Each auction can show 3–5 one-click bid buttons. By default they show:
- Current price + 1× increment
- Current price + 2× increment
- Current price + 5× increment
- Current price + 10× increment
Configurable per-auction (in the Bid form section) or globally in Design Studio.
Reverse auctions
For reverse-type auctions, the increment is a decrement — bids must be lower than the current price by at least this amount.
The same three modes apply, just inverted.
Common questions
"Can the bidder bid more than the minimum increment?"
Yes, always. The increment is a minimum floor. A bidder can bid any amount ≥ current + increment.
"What if my percentage rounds to less than 1 cent?"
The plugin enforces a hard minimum of 1 in your currency's smallest unit (cent / paisa / yen). For 0.01 percent on $1, the increment is rounded up to $0.01.
"Can I show different increments to different bidders?"
Use the wkafw_required_increment filter to vary by user (e.g. VIP bidders get smaller increments, new bidders get larger ones).