diff --git a/x/auction/types/auctions.go b/x/auction/types/auctions.go
index 53574412..021c8561 100644
--- a/x/auction/types/auctions.go
+++ b/x/auction/types/auctions.go
@@ -68,19 +68,18 @@ func (a BaseAuction) GetType() string { return "base" }
 
 // Validate verifies that the auction end time is before max end time
 func (a BaseAuction) Validate() error {
-	if a.ID == 0 {
-		return errors.New("auction id cannot be zero")
-	}
+	// ID can be 0 for surplus, Debt and collateral auctions
 	if strings.TrimSpace(a.Initiator) == "" {
 		return errors.New("auction initiator cannot be blank")
 	}
 	if !a.Lot.IsValid() {
 		return fmt.Errorf("invalid lot: %s", a.Lot)
 	}
-	if a.Bidder.Empty() {
+	// NOTE: bidder can be nil for Surplus and Collateral auctions
+	if a.Bidder != nil && a.Bidder.Empty() {
 		return errors.New("auction bidder cannot be empty")
 	}
-	if len(a.Bidder) != sdk.AddrLen {
+	if a.Bidder != nil && len(a.Bidder) != sdk.AddrLen {
 		return fmt.Errorf("the expected bidder address length is %d, actual length is %d", sdk.AddrLen, len(a.Bidder))
 	}
 	if !a.Bid.IsValid() {
diff --git a/x/auction/types/auctions_test.go b/x/auction/types/auctions_test.go
index e19e7423..decb2cc7 100644
--- a/x/auction/types/auctions_test.go
+++ b/x/auction/types/auctions_test.go
@@ -107,11 +107,6 @@ func TestBaseAuctionValidate(t *testing.T) {
 			},
 			true,
 		},
-		{
-			"0 id",
-			BaseAuction{ID: 0},
-			false,
-		},
 		{
 			"blank initiator",
 			BaseAuction{
@@ -135,7 +130,7 @@ func TestBaseAuctionValidate(t *testing.T) {
 				ID:        1,
 				Initiator: testAccAddress1,
 				Lot:       c("kava", 1),
-				Bidder:    nil,
+				Bidder:    sdk.AccAddress{},
 			},
 			false,
 		},