diff --git a/app/lib/billActions.ts b/app/lib/billActions.ts
index 74e640a..40bb27f 100644
--- a/app/lib/billActions.ts
+++ b/app/lib/billActions.ts
@@ -6,7 +6,7 @@ import { redirect } from 'next/navigation';
 import clientPromise from './mongodb';
 import { BillAttachment, BillingLocation } from './db-types';
 import { ObjectId } from 'mongodb';
-import { auth, withUser } from '@/app/lib/auth';
+import { withUser } from '@/app/lib/auth';
 import { AuthenticatedUser } from './types/next-auth';
 
 export type State = {
@@ -14,6 +14,7 @@ export type State = {
         billName?: string[];
         billAttachment?: string[],
         billNotes?: string[],
+        payedAmount?: string[],
     };
     message?:string | null;
 }
@@ -22,8 +23,47 @@ const FormSchema = z.object({
     _id: z.string(),
     billName: z.coerce.string().min(1, "Bill Name is required."),
     billNotes: z.string(),
+    payedAmount: z.string().nullable().transform((val, ctx) => {
+
+        if(!val || val === '') {
+            return null;
+        }
+
+        const parsed = parseFloat(val.replace(',', '.'));
+
+        if (isNaN(parsed)) {
+            ctx.addIssue({
+                code: z.ZodIssueCode.custom,
+                message: "Not a number",
+            });
+        
+            // This is a special symbol you can use to
+            // return early from the transform function.
+            // It has type `never` so it does not affect the
+            // inferred return type.
+            return z.NEVER;
+        }
+
+        if (parsed < 0) {
+            ctx.addIssue({
+                code: z.ZodIssueCode.custom,
+                message: "Value must be a positive number",
+            });
+        
+            // This is a special symbol you can use to
+            // return early from the transform function.
+            // It has type `never` so it does not affect the
+            // inferred return type.
+            return z.NEVER;
+        }
+  
+        return Math.floor(parsed * 100); // value is stored in cents
+
+      }),
   });
 
+  parseFloat
+
 const UpdateBill = FormSchema.omit({ _id: true });
 
 /**
@@ -52,7 +92,6 @@ const serializeAttachment = async (billAttachment: File | null) => {
     const fileContents = await billAttachment.arrayBuffer();
     const fileContentsBase64 = Buffer.from(fileContents).toString('base64');
 
-
     // create an object to store the file in the database
     return({
         fileName,
@@ -75,9 +114,12 @@ export const updateOrAddBill = withUser(async (user:AuthenticatedUser, locationI
 
     const { id: userId } = user;
 
+    const x = formData.get('payedAmount');
+
     const validatedFields = UpdateBill.safeParse({
         billName: formData.get('billName'),
         billNotes: formData.get('billNotes'),
+        payedAmount: formData.get('payedAmount'),
     });
 
     // If form validation fails, return errors early. Otherwise, continue...
@@ -92,6 +134,7 @@ export const updateOrAddBill = withUser(async (user:AuthenticatedUser, locationI
     const {
         billName,
         billNotes,
+        payedAmount,
     } = validatedFields.data;
 
     const billPaid = formData.get('billPaid') === 'on';
@@ -102,20 +145,23 @@ export const updateOrAddBill = withUser(async (user:AuthenticatedUser, locationI
     
     const billAttachment = await serializeAttachment(formData.get('billAttachment') as File);
 
-    // if there is an attachment, update the attachment field
-    // otherwise, do not update the attachment field
-    const mongoDbSet = billAttachment ? {
-        "bills.$[elem].name": billName,
-        "bills.$[elem].paid": billPaid,
-        "bills.$[elem].attachment": billAttachment,
-        "bills.$[elem].notes": billNotes,
-    }: {
-        "bills.$[elem].name": billName,
-        "bills.$[elem].paid": billPaid,
-        "bills.$[elem].notes": billNotes,
-    };
-
     if(billId) {
+
+        // if there is an attachment, update the attachment field
+        // otherwise, do not update the attachment field
+        const mongoDbSet = billAttachment ? {
+            "bills.$[elem].name": billName,
+            "bills.$[elem].paid": billPaid,
+            "bills.$[elem].attachment": billAttachment,
+            "bills.$[elem].notes": billNotes,
+            "bills.$[elem].payedAmount": payedAmount,
+        }: {
+            "bills.$[elem].name": billName,
+            "bills.$[elem].paid": billPaid,
+            "bills.$[elem].notes": billNotes,
+            "bills.$[elem].payedAmount": payedAmount,
+        };
+
         // find a location with the given locationID
         const post = await db.collection<BillingLocation>("lokacije").updateOne(
             {
@@ -144,6 +190,7 @@ export const updateOrAddBill = withUser(async (user:AuthenticatedUser, locationI
                         paid: billPaid,
                         attachment: billAttachment,
                         notes: billNotes,
+                        payedAmount
                     }
                 }
             });
diff --git a/app/lib/db-types.ts b/app/lib/db-types.ts
index 02ee9b8..fe4087d 100644
--- a/app/lib/db-types.ts
+++ b/app/lib/db-types.ts
@@ -11,20 +11,31 @@ export interface BillAttachment {
 /** bill object in the form returned by MongoDB */
 export interface BillingLocation {
     _id: string;
+    /** user's ID */
     userId: string;
+    /** user's email */
     userEmail?: string | null;
+    /** name of the location */
     name: string;
     /** the value is encoded as yyyymm (i.e. 202301) */
     yearMonth: number;
+    /** array of bills */
     bills: Bill[];
+    /** (optional) notes */
     notes: string|null;
 };
 
 /** Bill basic data */
 export interface Bill {
     _id: string;
+    /** bill name */
     name: string;
+    /** is the bill paid */
     paid: boolean;
+    /** payed amount amount in cents */
+    payedAmount?: number | null;
+    /** attached document (optional) */
     attachment?: BillAttachment|null;
+    /** (optional) notes */
     notes?: string|null;
 };
\ No newline at end of file
diff --git a/app/ui/BillEditForm.tsx b/app/ui/BillEditForm.tsx
index 39a62f4..6acb84f 100644
--- a/app/ui/BillEditForm.tsx
+++ b/app/ui/BillEditForm.tsx
@@ -2,7 +2,7 @@
 
 import { DocumentIcon, TrashIcon } from "@heroicons/react/24/outline";
 import { Bill } from "../lib/db-types";
-import { FC } from "react";
+import React, { FC } from "react";
 import { useFormState } from "react-dom";
 import { gotoHome, updateOrAddBill } from "../lib/billActions";
 
@@ -22,18 +22,24 @@ export interface BillEditFormProps {
 
 export const BillEditForm:FC<BillEditFormProps> = ({ locationID, bill }) => {
 
-    const { _id: billID, name, paid, attachment, notes } = bill ?? { _id:undefined, name:"", paid:false, notes:"" };
+    const { _id: billID, name, paid, attachment, notes, payedAmount } = bill ?? { _id:undefined, name:"", paid:false, notes:"" };
 
     const initialState = { message: null, errors: {} };
     const handleAction = updateOrAddBillMiddleware.bind(null, locationID, billID);
     const [ state, dispatch ] = useFormState(handleAction, initialState);
 
+    const [ isPaid, setIsPaid ] = React.useState<boolean>(paid);
+
     // redirect to the main page
     const handleCancel = () => {
         console.log('handleCancel');
         gotoHome();
     };
 
+    const billPaid_handleChange = (event: React.ChangeEvent<HTMLInputElement>) => {
+        setIsPaid(event.target.checked);
+    }
+
     return(
     <div className="card card-compact card-bordered max-w-sm bg-base-100 shadow-s my-1">
         <div className="card-body">
@@ -77,11 +83,32 @@ export const BillEditForm:FC<BillEditFormProps> = ({ locationID, bill }) => {
 
                 <div className="form-control w-32 p-1">
                     <label className="cursor-pointer label p-0">
-                        <span className="label-text">Paid</span> 
-                        <input id="billPaid" name="billPaid" type="checkbox" className="toggle toggle-success" defaultChecked={paid} />
+                        <span className="label-text flex-none w-[6.4em]">Paid</span> 
+                        <span>
+                            <input id="billPaid" name="billPaid" type="checkbox" className="toggle toggle-success" defaultChecked={paid} onChange={billPaid_handleChange} />
+                        </span>
                     </label>
                 </div>
 
+                {
+                    isPaid && <>
+                        <div className="form-control p-1">
+                            <label className="cursor-pointer label p-0">
+                                <span className="label-text flex-none w-[6.4em]">Amount</span> 
+                                <input type="text" id="payedAmount" name="payedAmount" className="input input-bordered text-right" placeholder="0.00" defaultValue={payedAmount === null || payedAmount === undefined ? undefined : payedAmount / 100}/>
+                            </label>
+                        </div>
+                        <div id="status-error" aria-live="polite" aria-atomic="true">
+                            {state.errors?.payedAmount &&
+                            state.errors.payedAmount.map((error: string) => (
+                                <p className="mt-2 text-sm text-red-500" key={error}>
+                                {error}
+                                </p>
+                            ))}
+                        </div>
+                    </>
+                }
+
                 <textarea id="billNotes" name="billNotes" className="textarea textarea-bordered my-2 w-full max-w-sm block" placeholder="Note" defaultValue={notes ?? ''}></textarea>
                 <div id="status-error" aria-live="polite" aria-atomic="true">
                     {state.errors?.billNotes &&
@@ -92,6 +119,11 @@ export const BillEditForm:FC<BillEditFormProps> = ({ locationID, bill }) => {
                     ))}
                 </div>
 
+                <div className="pt-4">
+                    <button type="submit" className="btn btn-primary">Save</button>
+                    <button type="button" className="btn btn-neutral ml-3" onClick={handleCancel}>Cancel</button>
+                </div>
+                
                 <div id="status-error" aria-live="polite" aria-atomic="true">
                     {state.message &&
                     <p className="mt-2 text-sm text-red-500">
@@ -99,8 +131,6 @@ export const BillEditForm:FC<BillEditFormProps> = ({ locationID, bill }) => {
                     </p>
                     }
                 </div>
-                <button type="submit" className="btn btn-primary">Save</button>
-                <button type="button" className="btn btn-neutral ml-3" onClick={handleCancel}>Cancel</button>
             </form>
         </div>
     </div>);