Do I need Form 10F if I already have a residency certificate?
It depends on what your certificate actually says. The declaration exists to supply the treaty information that the prescribed particulars call for and that a foreign certificate may not contain. Some authorities issue a certificate covering everything; many issue a short letter confirming residence and nothing else. Read your certificate against the particulars that are required rather than assuming it is sufficient because it is official. Where it is complete, the declaration adds nothing; where it is silent on a required particular, the declaration is how that gap is filled and the treaty rate supported.
Can I claim a treaty rate without an Indian tax registration?
In practice, no, because the declaration is filed electronically against an Indian tax identifier. That is the part that surprises people: a non-resident with no other Indian connection has to obtain Indian registration before the treaty rate the treaty itself gives them can be claimed in the ordinary way. It is a sequencing problem more than a difficulty. Start the registration well before the payment date, because the payer's deduction happens on a fixed date and will be made at the domestic rate if the paperwork is not in hand.
Who makes the declaration, me or the Indian payer?
You do. It is the declaration of treaty information that the non-resident recipient provides; the payer relies on it, together with your residency certificate, when deciding what to deduct. The payer will usually ask for both and keep them on its own file, because they are the support for a lower deduction if its position is examined. Send them as a set and send them early. Paperwork that reaches a payer's accounts department after the deduction has been computed does not change what was deducted, whatever the treaty says.
Does a company need this declaration or only individuals?
Nothing in the requirement turns on whether the recipient is a person or a company. It turns on two things: whether the recipient is a non-resident claiming a treaty rate on Indian income, and whether the residency certificate it holds contains all the prescribed particulars. A company's certificate from its home revenue authority is just as likely to be a short confirmation of residence as an individual's, and just as likely to leave a particular unstated. Check the certificate itself rather than the category of recipient.
My Indian bank is deducting the full rate on interest — will this help?
It will, for future payments, if the bank has it before it computes the deduction. The declaration and the residency certificate together are what let a payer apply the treaty rate at source, and a bank cannot apply a rate it has no support for. For deductions already made, the paperwork does not reach backwards: the excess over the treaty rate has to be claimed back through an Indian filing for the year concerned. That is why it is worth putting the declaration in place before the next interest credit date rather than after it.
What if my country's certificate is in a different format?
Format is not really the question; content is. What matters is whether the prescribed particulars appear somewhere in the certificate your own revenue authority issues, and authorities differ widely in how much they state. A certificate in another language will need a translation the payer can read, but a faithful translation of a document that omits a required particular still omits it. Compare the certificate line by line against the particulars required, and use the declaration to supply whatever is missing rather than trying to have the certificate rewritten.
How does the treaty tie-breaker work when both countries say I am resident?
As a sequence, stopping at the first test that gives an answer: where you have a permanent home available; if in both or neither, where your centre of vital interests is; then habitual abode; then nationality; and if all of those tie, the two tax authorities decide by agreement. It is evidential rather than elective — you do not choose your treaty residence, you demonstrate it, which makes the record of homes, family and time the substance of the claim. See tie-breaking dual residency.
How do I claim tax treaty benefits?
Two moments, and the earlier one matters more. Before a payment is made, you give the payer a declaration so they withhold at the treaty rate rather than the domestic one — a W-8BEN for a US payer, an NR301 for a Canadian payer, a residency certificate and Form 10F for an Indian one. After the year ends, you claim the position on a return, and the United States often wants it disclosed there in its own right. Claiming late means asking for a refund instead. See NR301 declarations.