The facts of this case are simple, but it will likely have significant impact upon many transactions involving the sale of real property. We decide a question recently presented to a number of courts in the United States, namely, whether the enforcement of a so called “due-on-sale” clause 3 in a home mortgage constitutes an unreasonable restraint on alienation in the absence of allegations of impairment to the security. A due-on-sale clause is a device commonly used in real property security transactions to provide, at the option of the lender, for acceleration of the maturity of the loan upon the alienation of the real property security. We conclude that we need not decide whether such a clause is a restraint on alienation because we also conclude that if it is indeed a restraint on alienation, it is a reasonable restraint and therefore enforceable.
The parties here include borrowers (Kenneth L. Dunham and F. Janine Uzzell) who sold their mortgaged home to a buyer (Glenn Swenson) who attempted to assume the borrowers’ low-interest mortgage, and include as well a bank (Ware Savings Bank) which threatened foreclosure unless the buyer renegotiated the mortgage and accepted the market interest rate. When the buyer purported to assume the mortgage, the bank attempted to enforce, through foreclosure, the due-on-sale clause in the mortgage. 4 The bor *65 rower and the buyer then brought this action against the bank, seeking an injunction against the foreclosure, and a declaration that the due-on-sale clause in the mortgage was unenforceable as an unreasonable restraint on alienation. A judge of the Superior Court allowed the bank’s motion for summary judgment, the plaintiffs appealed to the Appeals Court, and we transferred the case to this court on our own motion. We affirm.
Initially, we dispose of the plaintiffs’ claim that the bank waived its right to accelerate because it did not seek to enforce the clause until approximately three months had elapsed since the transfer. The prevailing rule is that under an ordinary acceleration clause in a mortgage the obligee has a reasonable time after the event which gives rise to the right to accelerate in which to elect to declare the indebtedness due.
Malouff
v.
Midland Fed. Sav.
&
Loan Ass’n,
We next examine the issue whether the due-on-sale clause is a restraint on alienation. There is substantial authority that it is not. “An examination of the law pertaining to restraints on alienation makes it clear that a ‘due on sale’ clause is not a restraint on alienation and cannot be so considered for any purpose, theoretical or practical.”
Occidental Sav. & Loan Ass’n,
v.
Venco Partnership,
We need not ponder further the question whether we are here dealing with a restraint on alienation, because we prefer to rest our decision on the conclusion that even if it is such a restraint, its nature is such that it is enforceable. As the plaintiffs acknowledge, even if the due-on-sale clause
*67
were a restraint on alienation in the traditional sense, its enforcement must be granted if it is a reasonable restraint. See
Bowen
v.
Campbell,
Before examining the bases upon which our decision rests, we outline some aspects of home mortgage transactions from the lender’s perspective.
5
At the outset, we note that the historic purpose of the due-on-sale clause was to protect the lender’s security interest
(Holiday Acres No.
3 v.
Midwest Fed. Sav. & Loan Assn,
Whatever the precise numbers, it is clear that lenders negotiate home loans with the realistic expectation that they will not be held to maturity, and interest rates are adjusted accordingly. The device used to activate the “early” (actually anticipated) payoff before maturity is the due-on-sale clause, which reduces interest rate risk by reducing the average time over which a mortgage loan is outstanding. Invalidating the due-on-sale clause would in effect extend the life of the average mortgage loan perhaps two or three times longer than the lender had originally anticipated, intensifying the lender’s risk of interest rate loss. It is fair to conclude that because of the reduced risk, use of an acceleration device lowers the interest rate at which the bank is willing to loan money. Viewed from this perspective, it can be argued that the mortgagors have already had the benefit of the clause which they now seek to invalidate.
Within the above context we turn to the policies which, on balance, make the clause reasonable and thus enforceable. They are: (1) the clause represents an equitable adjustment of rights between borrower and lender, (2) it may prevent State-chartered banks from operating at a competitive disadvantage with federally-chartered banks, and (3) it is a substantial benefit to the bank’s depositors and to the future borrowers from the bank.
1. The Clause Represents an Equitable Adjustment of Rights Between Lender and Borrower.
Many of the courts which have upheld the use of due-on-sale clauses have relied on the theory that the bank’s right to accelerate the outstanding debt upon sale of the property (and the concomitant right to obtain current interest rates by relending the money) is the counterpart of the borrower’s right to prepay the loan without penalty. These courts have reasoned that the borrower’s ability to “profit” from falling interest rates,
6
supported a like ability on the part of the
*69
lender to take advantage of interest rates in his favor. See, e.g.,
Crockett
v.
First Fed. Sav. & Loan Ass’n,
2. Federal Preemption.
Another problem which might occur if due-on-sale clauses were invalidated would be inconsistent enforcement of the clause depending on whether the lender is a State or federally-chartered institution. Federal law governing mortgage loans by federally-chartered institutions appears to require enforcement of due-on-sale clauses. “[A Federal savings and loan] association continues to have the power to include, as a matter of contract between it and the borrower, a [due-on-sale clause] .... [E]xercise ... of such option . . . shall be exclusively governed by the terms of the loan contract . . . .” 12 C.F.R. § 545.8-3(f) (1980). The *70 comptroller of the currency has proposed a similar rule for national banks issuing variable rate mortgages. 45 Fed. Reg. 64,196, 64,205 § 29.7 (1980). Recently, the Federal National Mortgage Association 7 has adopted an explicit policy requiring either an enforceable due-on-sale clause or an “early-call” 8 provision permitting the lender to require full payment after seven years, whether the property is sold or not. Wall Street Journal, Oct. 24, 1980, at 15, col. 2.
There is recent Federal case law which offers substantial support for the proposition that Federal regulations permitting due-on-sale clauses prevail as to federally-chartered institutions, even in the presence of conflicting State law.
Conference of Fed. Sav. & Loan Ass’ns
v.
Stein,
3. The Clause Protects the Bank’s Depositors and Benefits Future Borrowers.
The third base upon which we rest our decision is that the clause is of substantial benefit to both future borrowers from the bank and to the bank’s depositors. At first blush, the problem presented today appears to involve only the actual parties. A hasty reading leaves the simplistic impression that this case presents the classic confrontation between an institutional lender and a borrower, the borrower representing the stereotypical consumer resisting the foreclosure advances of the bank. The bank prevails. That, however, is a narrow and misleading interpretation. This court has not hesitated to use its power to prevent oppression and overreaching, when that power could be fairly exercised so as not to become itself an instrument of injustice. The result we reach today is consistent with our historic principles.
*72
Only on the most basic levels is this a struggle between the bank and the borrower to determine who will “profit” from inflation. See
Holiday Acres No. 3
v.
Midwest Fed. Sav. & Loan Ass'n,
The contest surely involves the adverse interests of past borrowers and future borrowers. Elimination of the clause “will cause widespread hardship to the general home-buying public.” Federal Home Loan Bank Bd. Adv. Op. No. 75.647, at 37 (July 30, 1975). Invalidation of the due-on-sale clause would have an immediate, concrete, and unfair impact upon the interests of future borrowers because the interest rate for their mortgage loans would have to be sufficiently high to offset the bank’s loss from outstanding low-interest loans which could then be prolonged through assumption. Viewed from this perspective, the issue thus becomes whether future borrowers who borrow from the bank through assumption of outstanding low-interest mortgages should be entitled to subsidization by those future borrowers who borrow directly from the bank. We perceive no policy reason for imposing such a result. “In the final analysis, one must conclude that people [who wish to assume low-interest mortgages in a high-interest market] are simply too eager to shift to others burdens properly belonging on their own shoulders.” Williams, supra at 916. 10
*73 The controversy can also be viewed as a conflict between the borrower-seller and the bank’s depositors. Massachusetts savings banks, cooperative banks, and credit unions are nonprofit corporations organized for mutual benefit. See generally G. L. c. 168 (savings banks), c. 170 (cooperative banks), c. 171 (credit unions). The same is true of federally-chartered savings and loan associations. 12 U.S.C. § 1464 (1976 & Supp. Ill 1979). The capital of these institutions comes from accumulated surplus of prior years’ operations, which is held in reserve for the benefit of the depositors. See G. L. c. 168, §§ 57, 59, 60, 60A; G. L. c. 170, §§ 37, 37A, 38, 40; G. L. c. 171, §§ 19-20. In a sense a savings bank is the alter ego of its depositors, and the risks faced by the institution expose all the depositors to potential harm. To the extent that yields on the investments of the institutions are reduced to unprofitable levels, the loss is borne by the individual depositor in the form of reduced returns on savings. “Calling a loan in order to get the full benefit of current interest rates is a legitimate and reasonable business practice — one which protects the Association members and their savings investments as well as fulfilling the statutory purpose of the association.” Century Fed. Sav. & Loan Ass’n, supra at 54.
4. Conclusion.
Although the question we decide today is a proper subject for judicial determination, the competing policies at issue in this case make it ideally suited to legislative resolution.* 11 As *74 we have demonstrated, there is ample support for allocation of inflationary gains to any of a number of groups — depositors, mortgagors holding outstanding low-interest mortgages, or future borrowers who must borrow to finance the purchase of a home. In the circumstances presented, if the bank is to be forbidden from enforcing a contract which allocates the gain to itself, it must be shown that the contract unreasonably restrains alienation. This has not been established, and so the contract is enforceable. 12
In the present economic circumstances, the visibility of large institutional lenders often makes such institutions the focal point for community concern. The right of the lender to accelerate a mortgage debt in order to renegotiate the loan at market interest rates will only be utilized by lenders when interest rates have risen. However, this coincidence should not obscure the fact that inflation has many causes, and the right to enforce a due-on-sale clause no more causes rising interest rates than the exercise of a borrower’s right to prepay his loan causes declining interest rates, or the carrying of an umbrella causes inclement weather. Both the right to prepay and the right to accelerate upon sale are protective devices relied upon by the community to moderate gains and losses in an uncertain economy. Because the due- *75 on-sale clause is counterbalanced by the borrower’s statutory right to prepay; because federally-chartered institutions might continue to enforce it as matter of Federal regulation irrespective of State court holdings; and because the clause offers substantial benefits to depositors and future borrowers, we conclude that if the clause does restrain alienation it does not do so unreasonably.
The judgment is affirmed.
So ordered.
Notes
This case does not involve either a “due-on-encumbrance” or a “consent-to-transfer” clause, two additional clauses familiarly found in such transactions. See
Tucker v. Lassen Sav. & Loan Ass’n,
The due-on-sale clause in the 1978 mortgage in the case at bar reads as follows: “The Mortgagor also covenants and agrees that in the event the ownership of the mortgaged premises or any part thereof shall by the voluntary or involuntary act of thé Mortgagor or by operation of law or otherwise become vested in any person, partnership, corporation, trust or *65 association other than the Mortgagor, the entire mortgage debt then remaining unpaid shall, at the option of the Mortgagee, forthwith become due and payable. Failure to exercise this option shall not constitute a waiver of the right to exercise the same in the event of a subsequent alienation of title by the Mortgagor or successor in title.”
This summary is compiled from information submitted by amici curiae, Savings Banks Association of Massachusetts, and the Massachusetts Mortgage Bankers Association.
In Massachusetts the Legislature has allocated this right to the borrower by statute. General Laws c. 183, § 56, allows certain borrowers to prepay a first mortgage without penalty at any time after three years from *69 the date of the note, and penalties for earlier prepayment are substantially limited.
The Federal National Mortgage Association (FNMA) is a government-chartered secondary mortgage corporation which buys residential mortgages from originating lenders at prices and upon terms that are set in advance. After obtaining a commitment from FNMA to purchase mortgages conforming to FNMA requirements, a bank can loan money to its customers who need mortgage financing even though the bank has no money of its own to lend. See A. Axelrod, C. Berger & Q. Johnstone, Land Transfer and Finance 91 (1978).
Acceleration of the mortgage debt is designated a “call” if initiated by the lender, and “prepayment” if brought about by the borrower.
G. L. c. 167, § 70, inserted by St. 1980, c. 335, § 1. See note 11, infra.
Other recent cases indicate the same concern. In
Mutual Fed. Sav. & Loan Ass’n
v.
Wisconsin Wire Works,
The Legislature has already addressed similar policy issues in its recent approval of variable rate mortgages, which, in practical effect, allocate gain from increased interest rates to the lender and the benefits of decreased interest rates to the borrower. G. L. c. 167, § 70. Variable rate mortgages, although different in detail, share some general restrictions with fixed rate mortgages containing prepayment and due-on-sale
*74
clauses, in that variable rate mortgages are limited in the amount and frequency of interest rate changes. Variable rate mortgages are but one legislative response to the problems encountered by borrowers and lenders alike in an unpredictable economy. See Va. Code § 6.1-330.34 (1978) (requiring prominent disclosure of due-on-sale clauses); Minn. Stat. § 47.20, subdivision 6 (1980) (invalidating the use of due-on-sale clauses in most residential housing). But see
Holiday Acres No. 3
v.
Midwest Fed. Sav. & Loan Ass’n,
In the case at bar, there are no allegations of fraudulent or unconscionable conduct by the bank, or laches, which might give rise to equitable defenses to be used by a borrower in such a situation. See
Crockett v. First Fed. Sav. & Loan Ass’n,
