Car bid strategy: how to set your maximum bid at auction
Set your maximum car bid before the auction: start from the real sale price, deduct VAT, fees, transport, prep and profit, then stop at your limit.
· 8 min read
Your maximum car bid is the realistic price the car will sell for in your market, minus VAT, auction fees, transport, reconditioning, a reserve for faults and the profit you need. Work it out before the auction opens, enter it as a proxy bid where possible, and never raise it during the sale. Everything above that number is money you pay to the seller instead of earning it.
Why the maximum car bid is calculated backwards
A profitable car bid starts at the end of the deal – the sale – and works back to the auction. The common mistake is the opposite: comparing the starting price at auction with a few retail adverts and treating the gap as profit.
That gap has to cover:
- VAT on the sale (all of it, or only on the margin).
- Buyer fees and document charges.
- Transport from the auction site.
- Reconditioning, tyres, servicing.
- Registration and inspection if the car is imported.
- The cost of holding the car until it sells.
- A reserve for faults the report did not show.
- Your profit.
The formula is simple:
Maximum bid = realistic sale price − VAT − costs − target profit
Step 1: Find the realistic sale price
The realistic sale price is what comparable cars actually sell for in your own country, after the usual discount – not the highest advert you can find.
How to get there:
- Compare like with like. Same model and generation, same engine and gearbox, similar mileage and equipment. A 1.5 TSI and a 2.0 TDI of the same year are different cars on the market.
- Use the median, not the average. One overpriced advert lifts the average; the median ignores it.
- Adjust for mileage and condition. If the auction car has 40,000 km more than the comparables, the price has to come down.
- Deduct your usual negotiation discount. If buyers typically get 2–4% off the asking price, apply it now.
For the worked example below, we use a 2020 Volkswagen Passat diesel to be sold in Germany. According to listings tracked by MyCarDealer in Germany in October 2026, 74 such cars were advertised with a median asking price of €17,999, with the middle half between €15,900 and €20,500, and a median mileage of 118,000 km. After a 3% discount, a realistic sale price for an average example is about €17,450.
For car dealers
Know your margin before you buy
MyCarDealer compares any car from an auction or listing with the market in your country and shows the net margin after VAT, transport and costs – and the maximum bid.
Request accessStep 2: Deduct VAT – the tax status changes everything
How much VAT comes off the sale price depends on whether the auction car is VAT-qualifying or sold under the margin scheme.
- VAT-qualifying car (bought net): you charge full VAT on the sale. In Germany, the net revenue is the sale price ÷ 1.19. You can reclaim VAT on the purchase, so you compare net with net.
- Margin-scheme car: under Articles 313–315 of the EU VAT Directive (2006/112/EC), implemented in Germany as § 25a UStG, VAT is due only on the difference between selling and purchase price. The VAT included in the margin is margin × 19/119 in Germany (21/121 in the Netherlands and Belgium, 22/122 in Italy, 23/123 in Poland). Under Article 323 you cannot deduct any VAT on the purchase.
Use the rate of the country where you sell, not where you buy. For more worked cases, see the VAT margin scheme calculator.
Step 3: Add up every cost
Costs are the part of a maximum bid most dealers underestimate, because the small items are left out. Use a fixed checklist and fill in real figures from your own suppliers and the platform's fee table.
| Cost item (net) | Example |
|---|---|
| Buyer fee and documents | €450 |
| Transport | €400 |
| Reconditioning (valet, paint touch-ups, tyres) | €600 |
| Reserve for hidden faults and warranty | €300 |
| Holding cost and advertising | €350 |
| Total | €2,100 |
These figures are illustrative. Reconditioning in particular varies widely; our guide to reconditioning costs for used cars gives a fuller budget.
Step 4: Set your target profit
Target profit is the minimum you need to earn on this car to make buying, preparing and selling it worthwhile – not the most you might get. Two common approaches:
- Fixed amount per car – simple and suits cheaper stock, where a percentage would produce too little to cover your time.
- Percentage of the sale price – suits more expensive cars, where the capital tied up and the risk are larger.
Many dealers combine them: a floor amount, plus a percentage above a certain price band. Whatever you choose, keep it consistent across the auction so you do not chase one car with a lower target than the rest. For context on what dealers actually earn, see car dealer profit margin.
Worked example: two maximum bids for the same car
With a realistic sale price of €17,450, costs of €2,100 and a target profit of €1,200, the same Passat gives two different maximum bids depending on its tax status.
Case A – VAT-qualifying (bid is net):
- Net revenue: €17,450 ÷ 1.19 = €14,664
- Minus costs: €14,664 − €2,100 = €12,564
- Minus target profit: €12,564 − €1,200 = €11,364 maximum net bid
Case B – margin scheme (bid is final):
- After VAT on the margin and costs, €1,200 must remain. The margin before VAT must therefore be (€1,200 + €2,100) × 1.19 = €3,927.
- Maximum bid: €17,450 − €3,927 = €13,523
- Check: VAT on the margin is €3,927 × 19/119 = €627; €3,927 − €627 − €2,100 = €1,200.
The margin-scheme car can carry a bid about €2,150 higher, because you pay VAT only on your margin. Bidding on a VAT-qualifying car with a margin-scheme limit is one of the most expensive errors at trade auctions.
MyCarDealer runs this calculation automatically for each car: it takes the weighted median of comparable cars in your country, applies your VAT rate and the lot's tax status, deducts your costs and shows the maximum bid. You can try it on one car with a free valuation.
How proxy and automatic bids work in online car bidding
A proxy bid is an instruction to the platform to bid on your behalf, in the platform's increments, up to the maximum you set. Other bidders see only the current price, not your limit. If someone outbids your maximum, you lose the lot – which, if your limit was right, is exactly what should happen.
Practical points for online car bidding:
- Enter the proxy early. It cannot be forgotten, and you are not tempted by the last-minute rush.
- Round down, not up. Bidding increments mean that €11,364 often becomes €11,300 or €11,250 in practice.
- Know the extension rule. Many timed auctions extend the closing time after a late bid, so the price can rise in the final minutes even if you have stopped watching.
- Check the reserve status. If the bid finishes below the reserve, the seller may offer the car to the top bidder later at a negotiated price – your limit still applies.
When to walk away from a bidding war
Walk away the moment the bid passes your maximum. A bidding war means at least one other buyer values the car more – because they have a customer waiting, a lower cost base, a higher-priced market, or a mistake in their numbers. None of those is a reason for you to pay more.
Signs you are about to overpay:
- You start recalculating the sale price upwards during the auction.
- You reduce the reserve for faults "because it looks clean".
- You tell yourself you will make it up on finance or warranty products.
- You are bidding because you have not bought anything all day.
If you lose a car at your limit, write down the final price. Over a few months, those notes tell you which segments other dealers value more highly – useful information for where to focus.
Frequently asked questions
How do I calculate the maximum I should bid on a used car?
Take the realistic sale price of comparable cars in your own market, deduct VAT according to the car's tax status, deduct all costs (fees, transport, reconditioning, reserve, holding costs) and deduct your target profit. The result is your maximum bid; never raise it during the auction.
Which costs must be deducted from the expected sale price?
Buyer fees and document charges, transport, reconditioning, inspection and registration for imported cars, a reserve for hidden faults, holding and advertising costs, and VAT – either on the full price for VAT-qualifying cars or only on the margin for margin-scheme cars.
How much target profit should a dealer build into a bid?
Enough to make the car worth buying, preparing and selling, given the capital tied up and the risk. Many dealers use a fixed minimum per car for cheaper stock and a percentage of the sale price for more expensive cars. The key is to keep the target consistent across all lots.
How do proxy and automatic bids work in online car auctions?
You enter your maximum, and the platform bids for you in its standard increments only as far as needed to stay in the lead, up to your limit. Other bidders do not see your maximum. If someone bids more, you are outbid and the platform stops.
When should I walk away from a bidding war?
As soon as the price passes your pre-calculated maximum. Another bidder may have a buyer waiting, a cheaper cost base or a better-paying market – or may simply be wrong. Losing a car at your limit costs nothing; winning it above your limit costs money.