THOMAS, Justice.

In the circuit court of Leon County the appellants sought an interpretation of organic and statutory law governing inheritance taxes in so far as they relate to appellants' effort to secure an order directing the appellee to refund to them $13,596.06 in such taxes.

The testatrix died in 1941. A tax return was filed two years later with the Collector of Internal Revenue, and the inheritance tax shown to be due was paid. About the same time a copy of the return was filed with the Comptroller, and he was paid $14,285.21, the sum that appeared due the State of Florida. More than five years later an additional amount of $10,146.31 principal, together with interest of $3,449.75, thought by appellants to be owing the state was paid. A few days afterward the Collector of Internal Revenue advised appellants that a credit of $16,075.40, which included the last payment of principal and interest, totaling $13,596.06, could not be allowed appellants because of the restriction in Section 813(b) of the United States Internal Revenue Code, 26 U.S.C.A. § 813(b), that no credit for state taxes could be allowed unless the payment was made within four years of filing the return.

The appellants then claimed a refund from the Comptroller of the principal and interest last paid. When the claim was rejected this suit followed.

We turn now to Section 11 of Article IX of the Constitution of Florida, F.S.A., inhibiting taxes upon inheritances by the state, but providing that such taxes may be required by the legislature "not exceeding in the aggregate the amounts which may by any law of the United States be allowed to be credited against or deducted from any similar tax upon Inheritances, or taxes on estates assessed or levied by the United States on the same subject * * *."

Section 813(b), supra, specifically provides that the tax imposed by the United States "shall be credited with the amount of any estate * * * taxes actually paid to any State * * *" and further that the "credit allowed * * * shall not exceed 80 per centum of the tax imposed * * * and shall include only such taxes as were actually paid and credit therefor claimed within four years after the filing of the return * * *." Italics supplied.

The pivotal question is this: If the tax is paid to the state too late for a credit on the Federal tax to be allowed does it follow that the state should be deprived of the money?

The language of the constitution is quite clear. The limitation of the inheritance tax to be levied under Florida law is the amount "allowed to be credited" by the federal law. The state's share does not depend upon the amount actually credited. Certainly the money attempted to be refunded does not represent any payment not allowable as a credit. That sum is a mere matter of mathematical computation. If the money paid the state is within the limitation the requirement of the constitution is met. Whether the credit on the federal government's part is defeated because of the restriction under federal law that it be paid within a stated time is purely a federal matter. To accept the appellant's argument would require us to hold that the state tax was dependent on the actual allowance of the credit by the federal government, and we are unwilling so to decide for the simple reason that such is not the true meaning of the language in the constitution. Such a construction would result in loss to the state of its share of all taxes paid beyond the four-year period, for if we uphold the appellants in their effort to obtain a refund the next step would be to exempt late payers on the theory that not being entitled to the credit at the deferred date there existed no obligation to the state.

The equitable considerations so forcefully presented by the appellants are most appealing, but they do not and cannot alter the clear meaning of the constitution. The complexity of the estate, the difficulty of fixing the expenses of administration, hence establishing the true value of the estate, the prolonged and complicated nature of the litigation in which the estate was involved, all tend to establish a reason or excuse for delay. But they do not convince us that we can bend the intent of the constitution to justify a refund either under Sections 215.26 or 198.29, Florida Statutes 1941, and F.S.A., because we do not feel that the payment to the comptroller was overpayment, payment of a tax not due, error, or excessive payment, and obviously we are powerless to deal with a tolling of the period of limitation fixed by federal statute.

We fail to see why the state should be penalized by a refund of more than thirteen thousand dollars, because of a circumstance not under the state's control, that is, appellant's delay.

This is the only point we feel obliged to decide in order to settle this controversy.

The decree is

Affirmed.

SEBRING, C.J., and TERRELL and HOBSON, JJ., concur.