Katamarans Expense Share

What is Katamarans Expense Share?

Katamarans Expense Share is a comprehensive expense tracking tool designed to help groups manage shared costs across multiple currencies.
You can access the app below or at share.katamarans.com

Perfect for international sailing trips, group vacations, roommates, or any situation where multiple people share expenses.

The app features secure cloud storage, multi-currency support with real-time exchange rates, and automatic balance calculations with optimised settlement plans.

Katamarans Expense Sharing App – User Guide

Key Features

✅ User Accounts – Secure sign-up and login with password management
✅ Multiple Yachts – Create and join unlimited expense groups
✅ Multi-Currency Support – Track expenses in any currency with automatic conversion

✅ Real-Time Exchange Rates – Automatic currency conversion using current rates
✅ Multi-Payer Support – Split payments when multiple people pay together
✅ Flexible Splitting – Choose exactly who shares each expense

✅ Cloud Storage – Your data is securely saved and accessible from any device
✅ Balance Calculations – Instantly see who’s owed money and who owes
✅ Settlement Plan – Get clear instructions on how to settle up efficiently

✅ Profile Management – Update email, password, and currency preferences
✅ Mobile-Friendly – Works perfectly on phones, tablets, and desktops
✅ Admin Dashboard – Manage users and view system information (admin users only)

Getting Started

Creating Your Account

Navigate to the app homepage
Click “Sign up”
Enter your email address and create a password (minimum 6 characters)
Click “Sign up” to create your account
You’ll be automatically logged in and taken to your yacht selection page

Note: Email confirmation is automatic – you can start using the app immediately!

Logging In

Enter your registered email and password
Click “Sign in”
You’ll see your list of yachts (or a welcome screen if this is your first time)

Forgot Your Password?

Click “Forgot password?” on the login page
Enter your email address
Click “Send Reset Link”
Check your email for the password reset link
Click the link and enter your new password twice
You’ll receive confirmation showing your email address

Managing Your Profile

Accessing Your Profile

From the yacht selection page, click the “Profile” button (or profile icon). You can view and update all your account settings here.

Changing Your Email Address

Go to the “Change Email” section
Enter your new email address
Click “Update Email”
Check your new email inbox to confirm the change

Updating Your Password

Go to the “Change Password” section
Enter your new password (minimum 6 characters)
Re-enter your new password to confirm
Click “Update Password”
Both passwords must match to update successfully

Setting Your Default Currency

In the “Preferences” section, find the “Default Currency” dropdown
Select your preferred currency from the extensive list
Click “Update Currency”
This becomes your default base currency for new yachts

Available Currencies: EUR, USD, GBP, JPY, AUD, CAD, CHF, CNY, SEK, NZD, and many more!

Working with Yachts (Expense Groups)

What is a Yacht?

A “yacht” is an expense group – a shared space where you and others can track expenses for a trip, event, or ongoing shared costs. Each yacht has:

A unique name you choose
A 6-character invite code for others to join
Its own set of participants and expenses
A selected base currency

Creating a New Yacht

From the yacht selection page, click “Create New Yacht”
Enter a descriptive name (e.g., “Greece Sailing 2024”, “Apartment Roommates”, “Bachelor Party”)
Click “Create”
Your yacht is created instantly with a unique invite code
You’ll be taken directly to your new yacht page

Tip: Use descriptive names to easily identify yachts later!

Joining an Existing Yacht

Click “Join Yacht” on the yacht selection page
Enter the 6-character invite code (provided by the yacht creator)
Click “Join”
You’ll be added to the yacht and taken to its page

Note: Ask the yacht creator to share the invite code with you. You’ll find it displayed on their yacht page.

Viewing Your Yachts

All yachts you’ve created or joined appear as cards on the yacht selection page. Each card shows:

Yacht name
Invite code (for inviting others)
Delete button (only for yachts you created)

Click any yacht card to open it.

Sharing a Yacht

Open the yacht you want to share
Find the invite code displayed near the top
Share this 6-character code with anyone you want to join
They can use it on the “Join Yacht” screen

Deleting a Yacht

⚠️ Only the yacht creator can delete a yacht

On the yacht selection page, find the yacht you created
Click the delete (trash) button on the yacht card
Confirm the deletion when prompted
Warning: This permanently deletes all expenses, participants, and data for this yacht!

Logging Out

Click the “Sign Out” button in the top right corner of any page. You’ll be returned to the login page. Your data remains safely stored and will be there when you log back in.

Multi-Currency Support

Understanding Base Currency

Every yacht has a base currency – this is the currency in which all balances, totals, and settlement plans are calculated and displayed. You can change this at any time.

Setting or Changing Base Currency

At the top of your yacht page, find the currency dropdown
Select your desired base currency
All expenses are instantly recalculated and converted to the new currency
All displays update automatically:
- Total Spend
- Total Spend per Person
- Balance Summary
- Settlement Plan
- Recent Expenses (showing converted amounts)

Adding Expenses in Different Currencies

When traveling or dealing with international costs, you can add expenses in their original currency:

When adding an expense, enter the amount
Select the original currency from the dropdown
Choose the expense currency (can be different from your base currency)
The app automatically converts to your base currency using real-time exchange rates

Example:

Your base currency is EUR
You pay $100 USD for dinner
Enter: Amount: 100, Currency: USD
The app converts it to EUR automatically (e.g., €92.50)
Recent expenses show: “€92.50 ($100.00 USD)”

Viewing Multi-Currency Expenses

In the Recent Expenses section:

Amounts are shown in your base currency
If the expense was in a different currency, the original amount appears in brackets
Example: “€92.50 ($100.00 USD)”

Currency Conversion Details

Exchange rates are fetched in real-time when you add an expense
Rates are stored with each expense for historical accuracy
When you change your base currency, all expenses are recalculated
If exchange rate fetching fails (no internet), a default rate of 1.0 is used

Note: Exchange rates are from reliable sources and updated regularly, but may differ slightly from rates you see elsewhere due to timing and sources.

Managing Participants

Adding Participants

In your yacht, find the “Add Participant” section
Type a person’s name in the text box
Click “Add Participant” or press Enter
Repeat for each person in your group

Best Practice: Add all participants before you start logging expenses!

Removing Participants

Find the participant in the Participants section
Click the red “X” button next to their name
The participant is removed immediately

⚠️ Important: You cannot remove a participant who has expenses associated with them. Delete their expenses first, then remove the participant.

Recording Expenses

Adding a New Expense

Go to the “Add Expense” section
Fill in all fields:

Description
What was purchased (e.g., “Groceries”, “Restaurant Dinner”, “Marina Fee”, “Fuel”)

Amount
The total cost (e.g., 150.00)

Currency
Select the currency in which the expense was paid

Who paid?

Click “Select participants”
Check the box next to each person who paid
You can select multiple people if they split the payment
Selected names will be highlighted

Split between:

Click “Select participants” in the second section
Check the box next to everyone who should share this cost
You can select any combination of participants
Selected names will be highlighted

Click “Add Expense”

The expense is instantly saved and all calculations update automatically!

Understanding “Who Paid” vs “Split Between”

These are two separate selections:

Who Paid: The person(s) who actually paid money
Split Between: The person(s) who should share the cost

Example:

Dinner costs €120
Bob pays the entire bill
Only Alice and Bob ate dinner (Charlie wasn’t there)

Who paid: Bob
Split between: Alice, Bob
Result: Alice owes Bob €60

Example with Multiple Payers:

Taxi costs $60
Alice and Bob each paid $30 at the time
The ride was shared by Alice, Bob, and Charlie

Who paid: Alice, Bob
Split between: Alice, Bob, Charlie
Result: Each person’s share is $20
- Alice paid $30, owes $20, net: +$10 credit
- Bob paid $30, owes $20, net: +$10 credit
- Charlie paid $0, owes $20, net: -$20 debt

Viewing Recent Expenses

The Recent Expenses section shows:

Description of each expense
Amount in your base currency
Original currency amount (if different) in brackets
Who paid
Who it’s split between
Delete button (trash icon)

Note: Expenses are listed from newest to oldest.

Deleting Expenses

Find the expense in the Recent Expenses section
Click the red trash icon next to it
The expense is deleted immediately
All balances and calculations update automatically

⚠️ Warning: Deleted expenses cannot be recovered! Double-check before deleting.

Understanding Balances

Total Spend

Displayed at the top of your yacht page in large numbers:

Shows the sum of all expenses in the yacht
Displayed in your selected base currency
Updates automatically when expenses are added or removed

Total Spend per Person

Shows how much each participant has paid (not their share):

Lists each participant with their total paid amount
Useful to see who’s been covering costs
Displayed in your base currency

Balance Summary

Shows each person’s net position – what they’re owed or what they owe:

Green (Positive) Numbers:
This person is owed money
Example: Alice: +€50 → Alice should receive €50

Red (Negative) Numbers:
This person owes money
Example: Bob: -€30 → Bob should pay €30

Zero:
This person is settled up – all even!

How Balances Are Calculated:
Balance = (What you paid) – (Your share of total expenses)

Example:

Alice paid €100
Alice’s share of all expenses is €75
Alice’s balance: +€25 (she’s owed €25)

Settlement Plan

The Settlement Plan shows exactly how to settle all debts with the minimum number of transactions.

What you’ll see:

Clear instructions: “Alice pays Bob €45”
All transactions needed to make everyone even
Amounts in your base currency

How to use it:

Follow each instruction in order
Mark off each payment as completed
When all payments are done, everyone’s balance is zero

Example Settlement Plan:

Alice pays Bob €45.00
Charlie pays Bob €30.00

After these two payments, everyone is settled!

Why these specific amounts?
The app uses an optimization algorithm to minimize transactions. It matches the largest debts with the largest credits first, continuing until everyone is even.

Tips & Best Practices

Before Your Trip

Create your yacht early and share the invite code with your group
Set your base currency to match your primary travel destination
Add all participants before the trip begins
Test with a small expense to make sure everyone understands

During Your Trip

Record expenses as they happen – don’t wait until later
Use descriptive names – “Groceries Day 3” is better than “Food”
Take advantage of multi-currency – enter expenses in whatever currency you paid
Check balances regularly to stay informed
Take screenshots of the settlement plan periodically

After Your Trip

Review all expenses for accuracy before settling
Share the settlement plan with your group (screenshot or share screens)
Follow the payment instructions to settle up
Keep the yacht for future reference or create a new one for your next trip
Consider leaving the yacht open until everyone confirms they’ve settled

Data Management

Only yacht creators can delete yachts – choose your creator wisely
All yacht members can add expenses – trust your group
Changes are instant – everyone sees updates in real-time
Your data is safe – stored securely in the cloud, accessible from any device
Log in from anywhere – access your yachts from any device with your account

Common Scenarios

Scenario 1: Simple Equal Split

Situation: Dinner for 4 people, one person pays the bill

Amount: €100
Who paid: Alice
Split between: Alice, Bob, Charlie, Diana

Result:
Each person’s share is €25

Alice paid €100, owes €25, net: +€75 (owed)
Bob paid €0, owes €25, net: -€25 (owes)
Charlie paid €0, owes €25, net: -€25 (owes)
Diana paid €0, owes €25, net: -€25 (owes)

Settlement:
Bob pays Alice €25
Charlie pays Alice €25
Diana pays Alice €25

Scenario 2: Unequal Participation

Situation: Groceries bought, but only some people used them

Amount: $60
Who paid: Bob
Split between: Bob, Charlie (only they ate the groceries)

Result:
Each person’s share is $30

Bob paid $60, owes $30, net: +$30 (owed)
Charlie paid $0, owes $30, net: -$30 (owes)

Settlement:
Charlie pays Bob $30

Scenario 3: Multiple Payers

Situation: Concert tickets bought together at the box office

Amount: £200 (for 4 tickets)
Who paid: Alice, Bob (they each paid £100 at the counter)
Split between: Alice, Bob, Charlie, Diana

Result:
Each person’s share is £50

Alice paid £100, owes £50, net: +£50 (owed)
Bob paid £100, owes £50, net: +£50 (owed)
Charlie paid £0, owes £50, net: -£50 (owes)
Diana paid £0, owes £50, net: -£50 (owes)

Settlement:
Charlie pays Alice £50
Diana pays Bob £50

Scenario 4: Multi-Currency Trip

Situation: International trip with expenses in different currencies

Your base currency: EUR

Expenses:

Hotel in USA: $300 USD (paid by Alice)
Dinner in UK: £120 GBP (paid by Bob)
Train in France: €80 EUR (paid by Alice)

All split between: Alice, Bob, Charlie

What the app does:

Converts $300 USD to EUR (e.g., €275)
Converts £120 GBP to EUR (e.g., €140)
Keeps €80 EUR as is
Total: €495
Each person’s share: €165

Result:

Alice paid €355 (€275 + €80), owes €165, net: +€190
Bob paid €140, owes €165, net: -€25
Charlie paid €0, owes €165, net: -€165

Settlement:
Bob pays Alice €25
Charlie pays Alice €165

Scenario 5: Complex Week-Long Trip

Situation: Multiple days, multiple expenses, different payers

The app handles everything automatically:

Tracks all expenses no matter how complex
Converts all currencies to your base currency
Calculates everyone’s total paid and total share
Generates the simplest settlement plan

Your job: Just add expenses as they happen. The app does the rest!

Frequently Asked Questions (FAQs)

Account & Authentication

Q: Do I need to verify my email after signing up?
A: No! Email confirmation is automatic. You can start using the app immediately after signing up.

Q: I forgot my password. What do I do?
A: Click “Forgot password?” on the login page, enter your email, and follow the reset link sent to your inbox.

Q: Can I change my email address?
A: Yes! Go to your Profile page and use the “Change Email” section. You’ll need to confirm the change via email.

Q: How do I change my password?
A: Go to your Profile page and use the “Change Password” section. You’ll need to enter your new password twice.

Yachts & Groups

Q: Can I use this with multiple groups at the same time?
A: Yes! Create or join as many yachts as you need. Each yacht is completely separate.

Q: How do I invite people to my yacht?
A: Share the 6-character invite code shown on your yacht page. Others can use it on the “Join Yacht” screen.

Q: Can I rename a yacht after creating it?
A: Currently, yacht names cannot be changed after creation. You would need to create a new yacht with the correct name.

Q: What happens if I delete a yacht?
A: All expenses, participants, and data for that yacht are permanently deleted. Only the yacht creator can delete a yacht.

Q: Can I leave a yacht I joined?
A: Yes, yacht members can remove themselves. However, this feature is currently in development. For now, ask the yacht creator to manage membership.

Currencies & Conversions

Q: What currency does this use?
A: You choose! Each yacht has a base currency you can set and change anytime. The app supports 30+ major world currencies.

Q: Can I track expenses in multiple currencies?
A: Yes! Add each expense in its original currency, and the app automatically converts it to your base currency using real-time exchange rates.

Q: Where do the exchange rates come from?
A: The app fetches current exchange rates from reliable financial data sources when you add an expense.

Q: What if I change my base currency later?
A: No problem! All existing expenses are instantly recalculated and converted to the new base currency.

Q: What happens if the exchange rate changes after I add an expense?
A: The exchange rate is saved with each expense at the time you added it, so your historical records remain accurate even if rates change.

Q: What if I don’t have internet when adding an expense?
A: The app will use a default exchange rate of 1.0. You may want to edit the expense later when you have internet to get accurate conversion.

Expenses & Calculations

Q: Can I edit an expense after adding it?
A: Not directly. You’ll need to delete the expense and add it again with the correct information.

Q: What happens if I accidentally delete an expense?
A: Deleted expenses cannot be recovered. Always double-check before clicking the delete button.

Q: Can someone pay more than their share?
A: Yes! This is handled automatically. If Alice pays €100 for something split equally with Bob, Alice gets credit for €100 and owes €50, resulting in a +€50 balance (Bob owes her €50).

Q: Why doesn’t my balance equal what I paid minus what I owe?
A: Your balance IS (what you paid) – (your share). Positive balance means you’re owed money, negative means you owe money.

Q: Can I split expenses unevenly (e.g., 60/40 instead of 50/50)?
A: Currently, the app only supports equal splits. If you need unequal splits, you can work around it by adding multiple expenses.

Settlement & Payments

Q: How does the settlement calculation work?
A: The app uses an optimization algorithm that minimizes the number of transactions needed to settle all debts. It matches the largest debts with the largest credits first.

Q: Why is the settlement plan different from what I expected?
A: The app finds the most efficient solution, which might not match intuitive person-to-person debts. The result is mathematically equivalent but with fewer transactions.

Q: Do I have to follow the settlement plan exactly?
A: The settlement plan is a suggestion for the most efficient way to settle. You and your group can arrange payments however you prefer, as long as everyone ends up even.

Q: Can the app track actual payments made?
A: Not currently. The settlement plan is a guide, but the app doesn’t mark payments as completed. You’ll need to track this separately with your group.

Data & Privacy

Q: Where is my data stored?
A: Your data is securely stored in the cloud and is accessible from any device when you log in with your account.

Q: Can I access my yachts from multiple devices?
A: Yes! Log in with your account from any device (phone, tablet, computer) to access all your yachts.

Q: Is my data secure?
A: Yes. The app uses industry-standard encryption and secure authentication to protect your data.

Q: Can other people see my data?
A: Only people who are members of the same yacht can see that yacht’s data. Your profile information is private to you.

Q: What happens if I delete my account?
A: Contact the administrator if you need to delete your account. Note that yachts you created may need to be transferred or deleted first.

Technical & Compatibility

Q: Does this work without internet?
A: You need internet to log in and sync data. Once loaded, basic functionality works offline, but you won’t be able to fetch exchange rates or save new data until you’re back online.

Q: What browsers does this work on?
A: The app works on all modern browsers: Chrome, Firefox, Safari, Edge, and mobile browsers.

Q: Can I use this on my phone?
A: Yes! The app is fully responsive and works perfectly on phones, tablets, and desktops.

Q: Can I print the settlement plan?
A: Yes! Use your browser’s print function (Ctrl+P or Cmd+P) to print the page, or take a screenshot.

Q: Is there a mobile app I can download?
A: Currently, the app is web-based. You can access it through your mobile browser, and it works great on mobile devices!

Usage Scenarios

Q: Can I use this for business expense tracking?
A: While you can use it for any shared expenses, it’s designed for casual group use. For business expenses with tax/reporting requirements, consider dedicated accounting software.

Q: Can I use this for ongoing expenses (e.g., roommates)?
A: Yes! Create a yacht for your ongoing situation and add expenses as they occur. The balances will accumulate over time.

Q: Can I use this for one-time events (e.g., a wedding)?
A: Absolutely! Create a yacht for the event, add all expenses, and settle up at the end.

Q: Can I track multiple trips with the same group of people?
A: Yes! Create a separate yacht for each trip. This keeps expenses organized and makes it easy to see what’s settled and what’s not.

Troubleshooting

Login & Account Issues

Problem: I can’t see the currency in the dropdown box
Solution: This has been fixed in the latest version. The selected currency text is now clearly visible. Try refreshing your browser.

Problem: The logout button is not visible on mobile
Solution: The logout button has been moved to the top right corner and should remain visible even when scrolling. Try refreshing your browser.

Problem: I’m not receiving the password reset email
Solution:

Check your spam/junk folder
Verify you entered the correct email address
Wait a few minutes – emails can sometimes be delayed
Make sure you have email service connectivity

Problem: My password reset link doesn’t work
Solution: Password reset links expire after a certain time. Request a new link and use it promptly.

Yacht & Expense Issues

Problem: I can’t remove a participant
Solution: You cannot remove participants who have expenses associated with them. Delete all their expenses first, then remove the participant.

Problem: My expense total looks wrong
Solution:

Check that all expenses are added correctly
Verify currency conversions are accurate
Make sure you’re viewing amounts in the correct base currency
Review the “Recent Expenses” list for any duplicate entries

Problem: The settlement plan seems wrong
Solution: The settlement plan uses mathematical optimization and may not match intuitive person-to-person debts, but it’s mathematically correct and minimizes transactions. All balances will be zero after following the plan.

Problem: Currency conversion seems incorrect
Solution:

Exchange rates fluctuate constantly – rates may differ from other sources
Rates are fetched at the time you add the expense
If you added the expense offline, a default rate of 1.0 may have been used
Double-check you selected the correct original currency

Display & Interface Issues

Problem: The page won’t load
Solution:

Check your internet connection
Try refreshing the browser (Ctrl+R or Cmd+R)
Clear your browser cache
Try a different browser
Check if you’re logged in

Problem: Changes aren’t saving
Solution:

Check your internet connection
Make sure you’re logged in
Try refreshing the page
Check for any error messages in red

Support & Contact

For additional help, questions, or feedback:

🌐 Visit: www.katamarans.com

Quick Reference Card

Action	Steps
Sign Up	Click “Sign up” → Enter email & password → Sign up
Create Yacht	Click “Create New Yacht” → Enter name → Create
Join Yacht	Click “Join Yacht” → Enter 6-digit code → Join
Add Participant	Type name → Click “Add Participant” or press Enter
Add Expense	Fill description, amount, currency → Select who paid → Select split between → Add Expense
Change Base Currency	Click currency dropdown at top → Select new currency
View Settlement	Scroll to “Settlement Plan” section
Delete Yacht	Yacht selection page → Click delete button → Confirm
Log Out	Click “Sign Out” button in top right corner