How to Use ChatGPT and Claude to Work Out TCS on Scrap Sale: A Step-by-Step Guide for CAs

A general AI assistant can compute TCS on a scrap sale correctly once you give it the rate, the sale value and the timing rule, and ask it to show its working. The rate is the part to control tightly: scrap was 1% under Section 206C(1) of the Income-tax Act 1961 and is 2% under Section 394 of the Income-tax Act 2025 from 1 April 2026, so a model relying on memory will often use the old figure.

This guide uses scrap as the worked case, but the same routine suits any TCS category. It works in ChatGPT, Claude or Gemini.

What can ChatGPT or Claude do here, and what should you never delegate?

Good use of the assistant	Never delegate
Applying a rate you pasted to a sale value	Confirming the rate and section for the transaction date
Working out which date triggers collection from a list of dates	Deciding whether the goods are "scrap" as defined
Producing a one-page working for the file	Judging whether the buyer or the sale falls in an exception
Building a table of many invoices, each with its own TCS	Client names, PAN or invoice numbers going into a public tool
Explaining the result in plain words	The final figure you sign off

The pattern: you paste the rule text, the assistant applies it, you verify.

Step 1: Set up a safe workspace

• Remove the seller's and buyer's names, PAN, GSTIN and invoice numbers. Write "Seller" and "Buyer", and use round or synthetic amounts where exact figures are not needed.
• Use a business plan with training on your data switched off, and stay within your firm's approved tools.
• One chat per computation, so an assumption from one case does not carry into the next.
• Store your prompts as templates. Our DPDP-safe prompt template library for CA firms shows how to anonymise inputs.

Step 2: Fix the facts before you prompt

Settle these yourself, from the law, before the assistant sees anything.

Question	Answer to confirm
Who collects?	The seller of the scrap collects from the buyer
Which section?	Section 206C(1) for sales before 1 April 2026; Section 394 of the Income-tax Act 2025 for sales from 1 April 2026. The site's Income-tax Act 2025 section mapper maps old numbers to new
What rate?	1% under the 1961 Act; 2% from 1 April 2026 (the Finance Act 2026 rationalisation moved scrap from 1% to 2%). Our TCS rates FY 2026-27 quick reference tracks current rates
What counts as scrap?	Waste and scrap from the manufacture or mechanical working of materials which is definitely not usable as such because of breakage, cutting up, wear or other reasons
When is TCS collected?	At the time of debit to the buyer's account or receipt of the amount, whichever is earlier
Is there a threshold?	None for scrap, so TCS applies from the first rupee
Base amount	Sale consideration; where GST is separately shown on the invoice, the usual position is that GST is left out of the base. Confirm against the circular your firm relies on

Rates change. Before using any rate here, check the current chart on the Income Tax Department website.

Step 3: Paste the rule and your inputs

You are helping a chartered accountant compute TCS on a scrap sale.
Do not use any rate or section from memory. Use ONLY the rule below.

RULE: The seller of scrap collects tax at source from the buyer.
Rate: [1% for a sale before 1 April 2026 (Section 206C(1), Income-tax
Act 1961) / 2% for a sale on or after 1 April 2026 (Section 394,
Income-tax Act 2025)]. TCS is collected at the earlier of (a) debit to
the buyer's account and (b) receipt of payment. There is no threshold.
TCS = rate x sale consideration, excluding GST shown separately.

INPUTS (anonymised):
- Sale value before GST: Rs [amount]
- GST charged separately: Rs [amount]
- Invoice / debit-to-buyer date: [dd Mon yyyy]
- Date payment received: [dd Mon yyyy]
- Buyer PAN available: [yes / no]

TASK:
1. State which rate applies from the invoice date and why.
2. State which date triggers collection and why.
3. Show TCS = base x rate step by step, rounded to the nearest rupee.
4. Show the total the buyer should be billed, including GST and TCS.
5. List every assumption. If anything is missing or ambiguous, ask me
   instead of assuming.

Step 4: Ask for a challenge pass

Run a second prompt in the same chat.

Now review your own answer. Check: (1) did you use the rate for the
correct date, (2) did you exclude GST from the base, (3) did you pick
the earlier of debit and receipt, (4) did you state any assumption I did
not give you. Point out each place where the answer would change if an
assumption is wrong.

This does not replace verification, but it surfaces silent assumptions cheaply.

Step 5: Worked example, checked by hand

A seller invoices scrap on 12 September 2026 on credit. Sale value is Rs 5,00,000, GST at 18% is Rs 90,000, and the buyer pays on 25 September 2026.

• Rate: the sale is after 1 April 2026, so 2% under Section 394.
• Trigger date: debit to the buyer's account on 12 September is earlier than the receipt on 25 September, so collection falls on 12 September.
• Base: Rs 5,00,000 (GST shown separately is excluded).
• TCS = 5,00,000 x 2% = Rs 10,000.
• Invoice total: 5,00,000 + 90,000 + 10,000 = Rs 6,00,000.
• Deposit: TCS collected in September is deposited by 7 October 2026, the 7th of the following month.

Now see how one outdated fact changes the answer. If the model applies the old 1% rate, TCS becomes Rs 5,000, an under-collection of Rs 5,000. If it includes GST in the base (5,90,000 x 2%), TCS becomes Rs 11,800, over-collecting Rs 1,800.

An assistant's answer to Step 3 is illustrative and varies run to run. You are checking that it lands on Rs 10,000 with the correct trigger date, not that its wording matches.

Where AI goes wrong

1. Outdated rates and section numbers. Many models still say 1% under Section 206C(1). For sales from 1 April 2026 the rate is 2% under Section 394. Pasting the rule for the right period fixes this.
2. Gross-versus-net base. Models often apply the rate to the invoice total including GST. Tell it the base excludes separately shown GST, and check the arithmetic.
3. The wrong trigger date. "Date of payment" is the common mistake. The rule is the earlier of debit to the buyer and receipt, so a credit sale triggers TCS at invoicing.
4. Silent assumptions. Buyer PAN available, no exemption applies, goods qualify as scrap. Insist on the assumptions list, and ask what happens if the goods are actually a by-product that is usable as such, which is not scrap under the definition.
5. Mixing up TCS with TDS. The seller collects TCS from the buyer. A model may describe the buyer deducting it. Read the first line of the answer.

Verify in 60 seconds

1. Enter the sale value, GST and date in CORAA's free TCS on scrap sale calculator.
2. Compare the rate, trigger date and rupee figure with the assistant's answer.
3. For other categories or thresholds, use the TCS rate and threshold calculator.
4. If the two disagree, check the date and rate first; they explain most gaps.

ChatGPT, Claude and Gemini: practical tips

• All three can process a small spreadsheet of invoices and add a TCS column. Ask for the formula so you can reproduce it in Excel.
• Save the rule-and-inputs prompt as custom instructions or a reusable project prompt where your tool supports it, and keep the rate line as the one thing you edit each time.
• Keep the challenge pass as a standing second prompt.
• Never treat a tool's stated rate as a source. The Income Tax Department chart is.

Frequently asked questions

What is the TCS rate on sale of scrap?

Under Section 206C(1) of the 1961 Act the rate was 1%. Under Section 394 of the Income-tax Act 2025, for sales from 1 April 2026, it is 2%. Confirm against the current official chart.

Who collects TCS on scrap?

The seller collects from the buyer, at the earlier of the debit to the buyer's account and the receipt of the amount.

Is there a minimum sale value before TCS applies?

No threshold applies to scrap, so TCS is collected from the first rupee.

Is GST included in the base?

Where GST is shown separately on the invoice, the usual position is that TCS is worked on the value excluding GST. Verify the position that your firm follows before relying on it.

Can I paste an actual invoice into ChatGPT or Claude?

Not with identifying details. Replace names, PAN, GSTIN and invoice numbers with labels and use your approved tool with data training off.

Which section replaced 206C?

Section 394 of the Income-tax Act 2025, effective 1 April 2026. The section mapper on this site lists old and new numbers side by side.

Where CORAA fits

A general assistant is fine for a single computation you will verify. When the same checks must run across a whole ledger with documented, repeatable results, see CORAA's deterministic core, which is built so the same inputs produce the same output every time, and start a trial.

Related: TCS rates FY 2026-27 quick reference.

Last reviewed: 26 September 2026