No source found says a finding in one binds the other, and the two statutes ask different questions — whether the credit was validly availed, and whether the expenditure was incurred. What the decisions do show is that each file is evidence in the other: an indirect-tax authority's listing of the supplier is not enough by itself to make the purchase bogus, and the GST authorities having allowed the credit on the same invoices is a fact the Assessing Officer has to deal with.
An accommodation-entry allegation on purchases almost never arrives alone. The same invoices carry an input tax credit, and the indirect-tax authorities run their own proceeding to reverse it with its own penalty. Clients assume the two must produce the same answer. They do not have to, and the reason is that they are not asking the same question.
The income-tax question is whether the expenditure was incurred and, if so, whether it was incurred for the business — which is why the answer can be the whole invoice, the profit element, or nothing at all depending on what the assessee can show about the goods. The indirect-tax question is whether the conditions for the credit were satisfied, which include matters that have no income-tax analogue at all, such as whether the supplier actually paid the tax to the government. A supplier who issued a real invoice for real goods and then defaulted on his own payment can lose the buyer his credit without anything at all following for the income-tax assessment.
So the two proceedings are not gateways to each other. But they are evidence in each other, and the decisions run in both directions.
On the department's side, the file usually opens with the supplier's name on an indirect-tax authority's list. The Mumbai Tribunal's answer to that is carried in this library: the listing is a good starting point for further investigation, and suspicion of the highest degree cannot take the place of evidence. That is the answer to a show-cause whose entire foundation is that another department has classified the supplier.
On the assessee's side, the state of the GST record is part of the evidence pack. The Kolkata Tribunal deleted a bogus-purchase addition where the purchases were backed by tax invoices, e-way bills, lorry receipts, weighment slips, the suppliers' GSTR-1 and GSTR-3B returns and banking payments, with the corresponding sales accepted, and treated the input credit having been allowed by the GST authorities as a further reason not to brand the purchases bogus on a search statement or suspicion. Note what that does and does not say: the credit having been allowed weighs in the assessee's favour as a fact; it is not described as concluding the Assessing Officer.
The practical consequences are about sequencing and consistency rather than about binding effect.
First, do not run the two files in separate rooms. The evidence that answers the income-tax notice — e-way bills, weighment slips, transport documents, quantity reconciliation — is largely the same evidence that answers the credit reversal, and the replies have to say the same thing. An income-tax reply that offers a percentage while the GST reply insists the supplies were genuine is a gift to whichever officer reads both.
Second, put the indirect-tax position on the income-tax record expressly: whether the credit on the disputed invoices has been allowed, reversed, or is under notice, and what stage the proceeding has reached. If it has been allowed, say so and annex it. If it has been reversed, say so first rather than leaving it to be produced against you, and explain the ground of reversal — a reversal for the supplier's non-payment is not a finding that no goods moved.
Third, watch the false-entry penalty. Its Explanation reaches an "invoice in respect of supply or receipt of goods or services or both issued by the person or any other person without actual supply or receipt of such goods or services or both" and an invoice "to or from a person who does not exist" — language framed on the indirect-tax model. Anything conceded in the GST proceeding about the reality of the supply is capable of being read straight into that definition. This is the single strongest reason to keep the two replies consistent.
What is missing is any authority on the binding question itself. No decision was found holding that an adjudication under the indirect-tax law operates as a finding in the income-tax assessment, or the reverse, and no Board circular or instruction was found telling officers what to do with a GST finding. Until there is one, plead the GST record as evidence, plead the listing as no more than a starting point, and do not tell a client that winning one file will win the other.
Two proceedings on the same invoices, run by different advisers, produce inconsistent records more often than not — and the inconsistency is what the department uses. Treating the GST file as part of the income-tax evidence pack, and vice versa, changes what goes into each reply and removes the department's easiest point.
We charge fees for our public utility work. Does that cost us charitable status under s.2(15)?
My return was only processed under 143(1). Does that stop the department reopening it later?
The Assessing Officer wants to tax what my client received on redemption of stock appreciation rights granted by the foreign parent as a perquisite. Is there Supreme Court authority on this?
Can a pharmaceutical company deduct the cost of gifts given to doctors?
I pay an annual fee to keep competitors out of my area. It recurs every year, so is it revenue expenditure?
My employee embezzled money from the business bank account. Can I write that off for tax?
My liability is certain but I cannot put a final figure on it yet and I will not pay it for years. Can I still deduct the provision?
I paid to have a railway station moved off my own mining lease so I could work the ground under it. Is that capital expenditure?
Every page in this library links to what it was written from, so you can check it rather than take our word for it.