Subject: Milestone [Number] Completed — Invoice [#] for Payment Dear [Client Name], I am writing to inform you that Milestone [Number] ("[(Description of Milestone)]") under our Agreement dated [Date] has been completed in accordance with the acceptance criteria set forth in Section [X]. Deliverables: - [List deliverables, e.g., "Prototype deployed to staging environment"] - [E.g., "Test results attached (Attachment A)"] - [E.g., "Design files uploaded to shared repository"] Invoice [#] in the amount of $[Amount] is attached. Per Section [Y] of the Agreement, payment is due within [14/30] days of this notice, i.e., by [Date]. Please confirm acceptance or provide any objections in writing within [5/7] business days. If no objections are received, the Milestone will be deemed accepted per Section [Z]. Thank you, [Your Name]

Subject: REMINDER: Payment for Milestone [Number] Overdue Dear [Client Name], This is a reminder that payment for Milestone [Number] in the amount of $[Amount] was due on [Date] and remains outstanding. As of today, the payment is [X] days overdue. Per Section [Y] of our Agreement, late payments accrue interest at [1.5]% per month ([18]% annually). Overdue amount: $[Principal] Accrued interest ([X] days): $[Interest] Total due: $[Total] Please remit payment immediately to avoid further interest charges and potential suspension of work per Section [Z]. I remain available to discuss any questions. Best regards, [Your Name]

FORMAL DEMAND FOR PAYMENT [Date] [Client Name] [Address] Re: Demand for Payment — Milestone [Number], Agreement dated [Date] Dear [Client Name]: I write on behalf of [Your Company] to demand immediate payment of $[Amount] due under our Agreement dated [Date] for completion of Milestone [Number]. FACTS: 1. On [Date of Completion], we completed and delivered Milestone [Number] in accordance with the acceptance criteria (Section [X]). 2. We provided notice of completion on [Date] and submitted Invoice [#]. 3. Payment was due on [Due Date]. As of today, [X] days have passed. 4. Despite multiple reminders, payment has not been received. AMOUNT DUE: - Principal: $[Amount] - Late payment interest ([X] days @ [1.5]% per month): $[Interest] - TOTAL: $[Total] LEGAL BASIS: Per Section [Y], you are obligated to pay each milestone invoice within [14/30] days. Section [Z] provides for interest at [1.5]% per month on overdue amounts. DEMAND: We demand payment of $[Total] within [7] days of this letter. If payment is not received, we will: 1. Suspend all work per Section [Suspension Clause]; 2. Pursue all available remedies, including arbitration/litigation and recovery of attorneys' fees per Section [Attorneys' Fees Clause]. Please contact me immediately to arrange payment. Sincerely, [Your Name] [Title]

NOTICE OF WORK SUSPENSION [Date] [Client Name] [Address] Re: Notice of Suspension of Work — Nonpayment of Milestone [Number] Dear [Client Name]: This letter serves as formal notice that, effective [Date — 14 days from today], [Your Company] will suspend all work under our Agreement dated [Date] due to your failure to pay Invoice [#] for Milestone [Number]. BACKGROUND: - Milestone [Number] was completed on [Date]. - Invoice [#] ($[Amount]) was issued on [Date], due [Due Date]. - Payment is now [X] days overdue. - We sent reminders on [Date] and a formal demand on [Date]. CONTRACTUAL RIGHT TO SUSPEND: Section [Z] of the Agreement provides: "If Client fails to pay any undisputed invoice within [X] days of the due date, Contractor may suspend work upon [14] days' written notice." SUSPENSION: Effective [Date], we will cease all work on the Project until payment is received in full, including: - Principal: $[Amount] - Accrued interest: $[Interest] - TOTAL: $[Total] We will resume work promptly upon receipt of payment. Please contact us immediately to resolve this matter and avoid project delays. Sincerely, [Your Name] [Title]

Subject: Response to Objections — Milestone [Number] Dear [Client Name], Thank you for your message raising concerns about Milestone [Number]. I address each point below: 1. [Client's Objection]: Our response: [Explanation referencing contract acceptance criteria, deliverables provided, etc.] 2. [Client's Objection]: Our response: [...] ACCEPTANCE CRITERIA: Per Section [X], Milestone [Number] is complete when [specific criteria]. All criteria have been met: - [Criterion 1]: [Evidence] - [Criterion 2]: [Evidence] DOCUMENTATION: Attached: - [E.g., "Test results showing 98% pass rate (requirement: 95%)"] - [E.g., "Email from [Date] in which you approved design"] We believe the Milestone has been properly completed. However, if you identify specific defects covered by the scope of work, we will address them promptly. Requests for additional features or changes beyond the original scope constitute change orders and will be quoted separately. Please confirm acceptance or provide detailed, written specifications of any alleged defects within [5] business days. Best regards, [Your Name]