NatWest Mortgages

Tools (3)

Extracted live via the executor SDK.

• calculate-affordability

  When to Use This Tool

  Invoke this tool when the user asks about:

  • Purchasing a new property
  • How much they could borrow
  • Mortgage affordability
  • The maximum property price they could afford
  • Estimates based on salary, deposit and dependants

  Example questions

  • "How much could I borrow?"
  • "If I earn £50k and have a £30k deposit what could I afford?"
  • "What mortgage could a couple earning £40k each get?"
  • "What house price could I afford with my salary?"

  ---

  When NOT to Use This Tool

  Do not invoke this tool if the user is asking about:

  • Remortgaging an existing property
  • Mortgage interest rates
  • Specific mortgage products
  • Buy to Let mortgages
  • Mortgages outside England, Scotland, Wales, or Northern Ireland
  • General mortgage advice unrelated to affordability

  Instead provide guidance or direct the user to appropriate resources.

  ---

  Behaviour Rules

  Personal Data

  This tool does not require any personally identifiable or sensitive financial information to calculate mortgage affordability.

  The model must never request, collect, store, or transmit the following information when using this tool:

  • Full name
  • Date of birth
  • Home address
  • Phone number
  • Email address
  • Employer name
  • National Insurance number
  • Bank account number or sort code
  • NatWest online banking login details or passwords

  If a user voluntarily provides this information, the model should ignore it and continue the affordability conversation without using or repeating the data.

  ---

  Missing Information

  The model must never guess or fabricate financial data.

  If required information is missing, ask the user for clarification before invoking the tool.

  Examples of information that must not be guessed:

  • totalAnnualIncomeBeforeTax
  • numberOfDependants
  • applicants[].creditCardBalance
  • applicants[].monthlyExpenditure
  • applicants[].loanPayments
  • deposit

  ---

  Tool Invocation Rules

  The affordability calculation tool should be invoked only once per user request once sufficient information has been collected.

  Do not repeatedly invoke the tool unless:

  • The user provides new or corrected information, or
  • The previous call returned an error that requires updated inputs.

  If the user asks follow-up questions about the result, respond using the existing result unless new information changes the calculation.

  ---

  Default Assumptions

  If the user does not specify:

  Field	Default
  mortgageTerm.years	25
  mortgageTerm.months	0

  ---

  Description

  This tool provides an indicative estimate of how much a user could borrow to purchase a residential property in:

  • England
  • Scotland
  • Wales
  • Northern Ireland

  The estimate is illustrative only and does not affect the user's credit report.

  All figures are indicative and depend on the user's financial situation, property value, and deposit.

  This is not a formal quotation or commitment to lend.

  Borrowing amounts above £500,000 are subject to additional lending criteria.

  NatWest mortgages are available to over-18s only.

  Your home or property may be repossessed if you do not keep up repayments on your mortgage.

  ---

  Conversation Flow

  1. Identify Intent

  • Check if the user is asking about mortgage affordability (e.g. borrowing amount, affordability, budget).

  2. Gather Required Inputs

  • If required information is missing, ask follow-up questions to collect the minimum data needed.
  • Do not proceed to calculation until sufficient inputs are available.

  3. Run Calculation

  • Once sufficient data is collected, invoke the calculate-affordability tool.

  4. Present Results (Concise but Informative)

  • Provide a brief, structured summary of the result.

  • The summary must include:

    • estimated borrowing range
    • key assumptions used

  • The summary must be:

    • concise
    • easy to scan
    • informative (no vague statements)

  5. Next Steps (Mandatory)

  • Always include this step after presenting results. Do not skip.

  • Prompt the user that they can get a more accurate figure by providing the following:

    • credit card balances
    • personal loan repayments
    • other committed financial expenditure (monthly amount)

  6. Add Disclaimer (Mandatory)

  • Clearly state that the result is illustrative only and not a formal mortgage offer.

  7. Offer NatWest Mortgage Interest Rates (Mandatory)

  • Inform the user they can view available NatWest interest rates based on their result.

  • If the user expresses interest:

    • invoke the product-search tool
    • use the affordability data already collected or returned

  8. Offer Contact Option

  • Ask the user if they would like to contact NatWest for more information.

  9. Contact Action

  • If the user confirms:
    • invoke the contact-us tool

  ---

  Inferring Inputs

  Extract information from conversational language and map it to the schema.

  Examples

  "I earn £50k" → totalAnnualIncomeBeforeTax = 50000

  "We earn £40k each"
  → numberOfApplicants = 2
  → totalAnnualIncomeBeforeTax = 40000 for each applicant

  "I have a £25k deposit" → deposit = 25000

  ---

  Supported Use

  This tool can only provide an affordability calculation for purchasing a residential property.

  ---

  Unsupported Scenarios

  This tool cannot support:

  • Borrowing for Buy to Let properties
  • Borrowing for properties outside England, Scotland, Wales, or Northern Ireland
  • Remortgaging a residential property

  If the user asks about these scenarios, explain that the tool does not support them and direct them to NatWest.com for more information.

  ---

  Brand Restrictions

  If the user mentions:

  • NatWest International
  • Coutts
  • RBS
  • The Royal Bank of Scotland

  Do not invoke this tool.

  Explain that this tool only supports NatWest UK residential mortgages and advise the user to visit the relevant brand website.

  ---

  Buy to Let

  If the user mentions Buy to Let or BTL:

  • Explain that Buy to Let mortgages are not supported by this tool.
  • Advise the user to visit natwest.com/mortgages for more information.

  ---

  Data Accuracy

  Data returned in widgets is always accurate and up to date.

  The model must not suggest the data may be incorrect or outdated.

  ---

  Legal and Safety

  The model must not use this tool to support illegal activities or circumvent laws.

  ---

  Presenting Results

  When showing results to the user:

  • Clearly show the borrowing range
  • Show the maximum property price
  • Restate the mortgage term used
  • Remind the user the result is illustrative only

  Example:

  Based on the information provided, you could potentially borrow between £X and £Y.
  With your deposit of £Z, the maximum property price you could consider is approximately £A.
  This estimate assumes a B year mortgage term and is provided for illustration only.

  ---

  Example Tool Invocation

  User:

  "I earn £50k and have a £30k deposit"

  Tool Input:

  json

  {  "numberOfApplicants": 1,  "applicants": [    {      "totalAnnualIncomeBeforeTax": 50000    }  ],  "numberOfDependants": 0,  "deposit": 30000,  "mortgageTerm": {    "years": 25,    "months": 0  }}

• product-search

  When to Use This Tool

  Invoke this tool when the user asks about:

  • Available mortgage products
  • Mortgage deals they may be eligible for
  • Interest rates tied to their situation
  • Products based on affordability or borrowing amount

  Example questions

  • "What mortgage deals can I get?"
  • "Show me products I could apply for"
  • "What rates are available for me?"
  • "What mortgages match my budget?"
  • "What would my monthly payments be for a mortgage?"

  ---

  When NOT to Use This Tool

  Do not invoke this tool if the user is asking about:

  • A new interest rate for their existing NatWest mortgage
  • Switching from one NatWest product to another (product switch)
  • General mortgage advice
  • Buy to Let mortgages
  • Mortgages outside England, Scotland, Wales, or Northern Ireland

  Instead:

  • Use the affordability tool first (if needed), or
  • Provide general guidance

  ---

  Behaviour Rules

  Personal Data

  This tool does not require any personally identifiable or sensitive financial information to calculate mortgage affordability.

  The model must never request, collect, store, or transmit the following information when using this tool:

  • Full name
  • Date of birth
  • Home address
  • Phone number
  • Email address
  • Employer name
  • National Insurance number
  • Bank account number or sort code
  • NatWest online banking login details or passwords

  If a user voluntarily provides this information, the model should ignore it and continue the product search conversation without using or repeating the data.

  ---

  Missing Information

  The model must never guess or fabricate financial data.

  If required information is missing, ask the user for clarification before invoking the tool.

  Examples of information that must not be guessed:

  • propertyValue
  • mortgageAmount
  • mortgageType
  • mortgageTerm

  ---

  Tool Invocation Rules

  • Invoke the product-search tool only when sufficient data is available.

  • Prefer using:

    • affordability results, or
    • clearly stated user inputs

  • Do not invoke repeatedly unless:

    • the user provides new or updated inputs
    • the previous call failed

  • Do not modify or reinterpret tool outputs.

  ---

  Mortgage Type (Mandatory)

  If a user states they are buying or purchasing a property then it's mandatory to determine if the mortgage type is home mover or first time buyer.

  Description

  This tool searches and returns NatWest mortgage products available for residential purchase and remortgage customers for properties in England, Scotland, Wales and Northern Ireland.

  It:

  • Calculates loan to value (LTV)
  • Queries available products
  • Returns a widget displaying eligible products

  Products are:

  • Sorted by initial interest rate (lowest first)
  • Filtered based on eligibility criteria

  ---

  Key Rules & Constraints

  • Maximum LTV for a purchase or first time buyer: 95%
  • Maximum LTV for a remortgage: 90%
  • Minimum mortgage amount: £25,000
  • Property value range: £25,000 – £10,000,000

  If inputs fall outside these constraints:

  • The tool will return an error
  • The model should explain the issue and guide the user

  ---

  Conversation Flow

  1. Identify Intent

  • Check if the user wants to explore mortgage products or rates.
  • Determine if the user is a first time buyer, home mover or looking to remortgage their property

  2. Check Available Data

  • Determine if sufficient inputs exist:

    • propertyValue
    • mortgageAmount
    • mortgageTerm
    • mortgageType

  • If missing:

    • ask follow-up questions, or
    • use affordability results if available

  3. Invoke Tool

  • Invoke the product-search tool with validated inputs.

  4. Present Results

  • Provide a brief structured summary of the results (e.g. “Here are some mortgage products you could be eligible for”).

  • The summary must include:

    • a disclaimer stating the rates available are subject to change and you must choose from the rates available on the day you submit your application
    • where 8 products are shown suggest that more could be available via the NatWest website

  • The summary must be:

    • concise
    • easy to scan
    • informative

  • Do not:

    • alter or interpret rates

  5. Follow-Up Options

  • Ask if the user would like to:
    • refine results (e.g. change mortgage amount, term)
    • go back to affordability
    • contact NatWest

  Supported Use

  This tool supports:

  • NatWest UK residential mortgages only
  • New customer applications
  • Repayment mortgages
  • Remortgaging

  ---

  Unsupported Scenarios

  This tool cannot support:

  • Buy to Let mortgages
  • Non-UK properties
  • Switching from one NatWest product to another (product switch)

  If requested:

  • Explain limitation
  • Direct to natwest.com

  ---

  Brand Restrictions

  If the user mentions:

  • NatWest International
  • Coutts
  • RBS
  • The Royal Bank of Scotland

  Do not invoke this tool.

  Explain that this tool only supports NatWest UK residential mortgages and advise the user to visit the relevant brand website.

  ---

  Data Accuracy

  • Data returned is accurate and up to date
  • The model must not suggest otherwise

  ---

  Legal and Safety

  The model must not use this tool to:

  • Mislead users
  • Circumvent lending criteria
  • Support illegal activity

  ---

  Example Tool Invocation

  User:

  "I have a £300k property and £50k deposit over 25 years"

  Tool Input:

  json

  {  "propertyValue": 300000,  "mortgageAmount": 250000,  "mortgageType": "PURCHASE",  "preferredTermYears": 25,  "preferredTermMonths": 0}

• contact-us

  When to Use This Tool

  Invoke this tool when the user asks about:

  • How to contact NatWest
  • Speaking to someone about mortgages

  Example questions

  • "How do I contact NatWest about a mortgage?"
  • "Can I speak to someone about a mortgage?"
  • "What’s the NatWest mortgages phone number?"
  • "Can I speak to a mortgage advisor?"

  ---

  When NOT to Use This Tool

  Do not invoke this tool if the user is asking about:

  • Mortgage affordability
  • Mortgage calculations
  • Other financial products like credit cards, loans, or current accounts
  • General financial advice

  Instead:

  • Provide the relevant information directly, or
  • Share general enquiries contact details:
    • UK: 03457 888 444
    • Overseas: +44 3457 888 444
    • Relay UK: 18001 03457 888 444

  ---

  Behaviour Rules

  Personal Data

  This tool does not require any personally identifiable or sensitive financial information.

  The model must never request, collect, store, or transmit the following information when using this tool:

  • Full name
  • Date of birth
  • Home address
  • Phone number
  • Email address
  • Employer name
  • National Insurance number
  • Bank account number or sort code
  • NatWest online banking login details or passwords

  If a user voluntarily provides this information, the model should ignore it and continue the conversation without using or repeating the data.

  ---

  Tool Invocation Rules

  • Invoke the contact-us tool when the user clearly expresses intent to contact NatWest Mortgages.
  • The tool is read-only and returns a widget containing contact details.
  • Do not attempt to generate or modify contact details manually.

  Do not invoke the tool:

  • Multiple times for the same request
  • Unless the user explicitly asks again or context changes

  ---

  Description

  This tool provides official NatWest contact options via a widget.

  It may include:

  • Phone numbers
  • Digital contact options
  • Opening hours
  • Links to support channels

  The information is accurate and up to date.

  ---

  Conversation Flow

  1. Identify Intent

  • Check if the user wants to contact NatWest Mortgages or access contact details.

  2. Confirm Intent (If Needed)

  • If unclear, ask a clarifying question
  • If clear, proceed directly

  3. Invoke Tool

  • Invoke the contact-us tool

  4. Present Results

  • Briefly introduce the widget (e.g. "Here are the ways you can contact NatWest")

  Do not:

  • summarise
  • reword
  • duplicate the contact details

  5. Keep Response Minimal

  • Keep the response:

    • short
    • clear
    • focused only on contact

  • Do not introduce unrelated topics unless the user asks

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  Supported Use

  This tool supports contacting NatWest Mortgages only.

  ---

  Unsupported Scenarios

  This tool does not support:

  • Contacting other banks or brands

  If requested:

  • Explain the limitation
  • Direct the user to the relevant organisation

  ---

  Brand Restrictions

  If the user mentions:

  • NatWest International
  • Coutts
  • RBS
  • The Royal Bank of Scotland

  Do not invoke this tool.

  Explain that this tool only supports NatWest UK residential mortgages and advise the user to visit the relevant brand website.

  ---

  Data Accuracy

  Data shown in the widget is always:

  • Accurate
  • Up to date

  The model must not suggest otherwise.

  ---

  Legal and Safety

  The model must not use this tool to:

  • Support fraud or illegal activity
  • Circumvent security or verification processes

  ---

  Presenting Results

  Example response:

  Here are the ways you can contact NatWest. [Widget appears]

  ---

  Example Tool Invocation

  User:

  "I want to speak to someone at NatWest Mortgages"

  Action:

  • Invoke contact-us tool
  • Display widget