{"id":"acct-milestone-invoice-retainage","audience":"accounting","category":"finance-work","track":"finance","technique":"constraints","level":"intermediate","title":"Size a milestone invoice, retainage and what is not yet billable","free":false,"task":"You're billing a fixed-fee contract on milestones. Write a prompt for plain text with lines starting \"Invoice now:\", \"Retainage:\", \"Cash expected:\" and \"Not yet billable:\", each with the math. Only completed and accepted milestones are billable. Retainage is the percentage the customer holds back on each invoice. Under 70 words. No bullets or numbering.","materialLabel":"Contract terms and milestone status (attached to your prompt automatically)","material":"CONTRACT BILLING STATUS - Cobalt Freight Ltd, fixed fee $60,000, Nov 6, 2026\n\nMilestones:\nM1 - Design: 30% of fee - completed and accepted Oct 28\nM2 - Build: 40% of fee - about 50% complete, not yet accepted\nM3 - Launch: 30% of fee - not started\n\nBilling terms: each milestone is invoiced when completed and accepted. The customer withholds 10% retainage from each invoice, released at final acceptance.\n\nNote: the project manager says 'M2 is basically done, bill half of it now.' Terms say invoicing happens only on acceptance. M1 has not yet been invoiced.","rules":[{"type":"plainText"},{"type":"maxWords","max":70},{"type":"maxBullets","max":0}],"promptHints":[{"label":"Names the four lines","patterns":["invoice now","retainage","cash expected","not yet billable"]},{"label":"Limits to accepted milestones","patterns":["accepted"]},{"label":"Gives the retainage rule","patterns":["10%"]},{"label":"Ignores partial billing","patterns":["ignore.*partial"]},{"label":"Caps length","patterns":["\\d+\\s*words","plain"]}],"mistakes":[{"title":"Billing half of M2","why":"The AI invoices M1 plus 50% of M2.","fix":"Add: \"Only completed and accepted milestones are billable; ignore partial-completion billing.\"","checks":["r0","r2"]},{"title":"Forgetting retainage","why":"The AI expects $18,000 cash.","fix":"Say: \"Cash expected = invoice minus 10% retainage.\"","checks":["r1"]},{"title":"Wrong not-yet-billable total","why":"The AI leaves out M3 or counts M1 again.","fix":"Add: \"Not yet billable: M2 and M3 amounts added.\"","checks":["r2"]},{"title":"Markdown extras","why":"The AI adds bold labels, headings and a closing note.","fix":"Say: \"Plain text, no bold. Output only the lines asked for.\"","checks":["plainText","maxBullets"]},{"title":"Trusting the AI to count words","why":"AI is bad at counting and runs past word limits.","fix":"Ask for fewer words than the real cap and keep each line short.","checks":["maxWords"]}],"hint":"Billing follows acceptance, not progress. State the rule, retainage and the four lines.","rubricLabels":["The line starting \"Invoice now:\" shows 30% x $60,000 = $18,000 for M1 only","The line starting \"Retainage:\" shows 10% x $18,000 = $1,800 and the line starting \"Cash expected:\" shows $18,000 - $1,800 = $16,200","The line starting \"Not yet billable:\" shows $24,000 (M2) + $18,000 (M3) = $42,000, and the project manager's half-billing of M2 isn't included"]}